Whistle-blowing has been on the increase and so has the rate at which secret documents are being leaked to the news media.  The longer Tony Blair has remained Prime Minister, the greater it seems has been the number of unauthorised disclosures.  Nicholas Jones, author of a new book, Trading Information: Leaks, lies and tip-offs, examines the background to the recent upsurge in the illicit flow of confidential information. And, against the background of recent cases involving whistleblowers, he assesses the motives for the government’s latest attempt to strengthen the Official Secrets Act.

Opposition to the war in Iraq has undoubtedly been the key factor in motivating many of the leaks which have given rise to the greatest political difficulties for Tony Blair.

Margaret Thatcher had been there before him: most of the illicit disclosures which caused her so much grief in the 1980s related to what were also perceived to have been acts of aggression by the state, whether it was the delivery of Cruise missiles, the Falklands War or the programme of pit closures which precipitated the 1984-5 miners' strike.

By the end of her premiership leak inquiries were averaging thirty five a year, almost twice the rate when Thatcher entered Downing Street. Blair's government has proved to be no exception. Leaks which have warranted an investigation by the Cabinet Office and sometimes the police have been running at an unprecedented level.

Blair's support for the American-led invasion of Iraq in March 2003 became the trigger for a succession of highly embarrassing disclosures relating to the conduct of the war and the role of the intelligence services. Disarray within the security services and the Metropolitan Police over the response to terrorist attacks has only served to accelerate the flow of leaked documents and correspondence.

If confirmation were needed of the depth of alarm within the government, compelling evidence is provided by the Intelligence and Security Committee. Its annual report to Parliament, published in June 2006, reveals that the Home Office is hoping that a bill to toughen the Official Secrets Act can be included in the new legislative programme which is to be announced in the Queen's Speech on 15 November.

The government's intention is 'to remove the common law defence of duress of circumstance' in order to clamp down on the increase in unauthorised disclosures by members and former members of the intelligence and security agencies; an increase of the maximum two year jail sentence is also being proposed, possibly to as high as four years.

The defence of 'duress of circumstance', the so-called 'defence of necessity', was established as a result of David Shayler's appeal to the House of Lords and would have been used by Liberty in its defence of another whistleblower, Katharine Gun, had it not been for the government's decision to drop its prosecution under the Official Secrets Act five days before the start of her trial in February 2004.

A further indication about the likely scope and timing of any new legislation could well coincide with the Old Bailey trial in October of a former civil servant and political researcher who have been charged with offences under the Official Secrets Act. They have both pleaded not guilty to the unauthorised disclosure of a conversation in April 2004 between Tony Blair and George Bush during which the US President was said to have suggested bombing the headquarters of the Arabic television channel Aljazeera.

Like Thatcher in her day, Blair has discovered to his discomfort that the level of hostile leaking against the government of the day can become a fairly accurate indicator of rising political unpopularity. The more controversial the policies; the more frequently the public believes it is being misled; and the wider the concern about the threat to civil liberties, the greater the temptation for civil servants and others in the know to slip out information in the hope of exposing their political masters or of assisting in campaigns to challenge contentious decisions.

Widespread use of photocopiers, which quickly came to be regarded as the 'leaker's friend', have offered a ready means of obtaining duplicate copies; the rapid introduction of fax machines, the internet and e-mails have opened up endless opportunities for the unauthorised distribution of data.

With a few flicks of the finger at a key board page upon page can be called up for scrutiny on a computer screen. Although the flow of e-mails and telephone calls can be tracked with great precision, once there is a hard copy in printed form, and once it has been stripped of identifying marks, a potential leaker can get to work.

As I can readily testify, the journalistic pulse quickens on spotting a strange looking letter in the post and then finding that it contains a set of confidential documents.

Secret information about the diplomatic manoeuvrings ahead of the Iraq war began to leak out in the lead-up to the offensive, several months before the late Dr David Kelly gave his unauthorised briefings to three BBC correspondents expressing his doubts about the validity of the dossier on Saddam Hussein's weapons of mass destruction.

Early in March 2003, three weeks before the start of the invasion of Iraq, the Observer published a 'top secret' American memo which had been leaked from GCHQ in Cheltenham; another name was about to be added to the roll call of Britain's most celebrated post-war leakers.

Here was a genuine Sunday newspaper exclusive: 'Revealed: US dirty tricks to win vote on Iraq war'. A second headline filled in the details: 'Secret document details American plan to bug phones and e-mails of Security Council members'.

Almost twelve months elapsed before Katharine Gun, a Mandarin Chinese translator at GCHQ, was able to give an account of the day she surprised herself by becoming a whistleblower and emerging as a transatlantic cause celebre.

Gun's superiors in Cheltenham must have thought there could hardly have been a more unlikely whistleblower. Then aged twenty-eight, she was a linguist, the daughter of a university lecturer, and she had spent two years at the GCHQ eavesdropping centre translating Mandarin Chinese intercepts into English.

Along with her colleagues she received an e-mail on Friday 31 January 2003 in which the US National Security Agency sought the help of GCHQ in discovering the voting intentions of six states with swing votes on the UN Security Council.

After spending the weekend wrestling with her conscience, she went back to work on Monday, convinced that if anything was going to stoop the war, this might be it. She retrieved the e-mail from her classified in-box, copied and pasted it into a Word document, printed off a copy and walked out of GCHQ with it in her bag.

Gun, who was dismissed from GCHQ in June 2003, had to wait until mid-November before being formally charged under the Official Secrets Act with having disclosed classified security and intelligence information without official authority.

When she appeared before Bow Street magistrates' court and was committed for trial, she did not dispute having the leaked the e-mail but denied breaching the Act because her disclosure had exposed 'serious illegality and wrong doing' on the part of the US government which had attempted to subvert the British security services, and her action was 'necessary to prevent an illegal war in which thousands of Iraqi civilians and British soldiers would be killed or maimed'.

As the trial approached, Gun's lawyers indicated that they were convinced the case would hinge of the advice given to the Cabinet about the legality of the war, a tactic designed to play on ministers' fears that punishing an anonymous junior official could prove fatal to the government when it was withholding information the public.

In the event the prosecution was dropped and, at a hearing in February 2004 which lasted for only eighteen minutes, Mark Ellison, counsel for the Crown, told the court there was 'no longer sufficient evidence for a realistic prospect of conviction'. The day before hearing the defence had demanded to see all government papers relating to the legality of the war and most newspapers were convinced that it was serious doubts about the Attorney General's advice which forced the government to abandon the prosecution.

Walking free from the Old Bailey, Gun told waiting journalists she had acted throughout with 'decency and honesty'. She had not been looking for information to leak but had been horrified on discovering that British intelligence services were being asked to undermine the whole democratic process of the UN.

Six months after the case was dropped Gun joined whistleblowers from several other countries in establishing the Truth-Telling Coalition, which aimed to stand by people who leaked sensitive information. One immediate aim of the group was to start a campaign for a fundamental reform of the Official Secrets Act so that it distinguished between 'espionage breaches which genuinely endanger national security and public-spirited whistle-blowing'.

Adding his voice to the call for a review of the secrecy laws was David Shayler, a former MI5 intelligence officer who was sentenced to six months' imprisonment in 2002 for passing classified information to the Mail on Sunday. Although it did not help in his own case, Shayler's appeal to the House of Lords did succeed in establishing the 'defence of necessity' which Liberty had planned to use on Gun's behalf.

Previously the judges had always rejected the argument put by defence lawyers that civil servants and other had been acting in the public interest when they leaked classified information. In a change to what had otherwise been a blanket ban, the Law Lords ruled that if defendants could show they were acting out of necessity or under duress, the jury had the right to hear them out.

Despite a judge's direction that there should be a conviction, a jury acquitted Clive Ponting in 1985 after he leaked documents about the sinking of the General Belgrano during the Falklands war and Liberty believed the Law Lord's concession, which would have allowed Gun to put her case to a jury and plead the defence of necessity, would have been a trump card, especially at a time when public opinion was do divided about the Iraq war.

Although mightily relieved at the time that the prosecution was dropped, Gun told me subsequently that she regretted the fact that she missed her day in court and had not been able to argue that her action had been 'necessary to prevent an illegal war'. If the case had gone to trial she might have been able to set a precedent and establish the 'defence of duress of circumstance' thus making it harder for the government to amend the Law Lords' ruling.

A review of the secrecy laws was announced the day after Gun's case collapsed. The Prime Minister's official spokesman told lobby correspondents that Tony Blair had been 'disappointed' by the outcome and thought it was only 'a matter of common sense' that government departments should consider whether changes were needed.

A month later the Sunday Times reported that the then Home Secretary, David Blunkett, was conducting the review and was seeking to find ways to 'gag the blabbers'. Apparently his intention was to restrict the defence of necessity by requiring defendants to show they had used 'every possible avenue' to alert the authorities before they engaged in illegal conduct.

News that the law might be tightened alarmed the National uUnion of Journalists, which repeated its longstanding demand for the introduction of a wide ranging defence to allow whistleblowers to argue they had acted in the public interest. Shayler suggested that one solution would be to allow intelligence officers and other civil servants to give evidence to parliammentary committees without fear of prosecution.

Blunkett's promised tightening of the secrecy laws did nothing to stem the continuing flow of unauthorised disclosures aimed at exposing the danger to Britain of the government's continuing support for military action.

What seemed at the time to be the leak which could cause Blair the most political damage was fired with almost deadly precision in the closing stages of the 2005 general election campaign. Ten days before polling day, much to the annoyance of the Labour Party's campaign team, the Mail on Sunday's front page exclusive succeeded in pushing Iraq to the top of the election news: 'The proof: Blair was told war could be ruled illegal'. For the previous two years the Prime Minister had steadfastly refused to publish the full advice given by the Attorney General, Lord Goldsmith.

Although the Mail on Sunday was only able to give a brief outline of the contents of what it said was a secret thirteen-page document, the text of the six key paragraphs was leaked to Channel 4 News, Guardian and BBC. Finally Downing Street opted for full disclosure and the advice was posted in full on the No.10 website.

Labour's re-election in May 2005 did nothing to lessen doubts about the legality of the war and as the months went by each new revelation about the government's handling of defence and security issues only served to strengthen opposition to the continued deployment of British troops in Iraq.

In January 2006, under the headline 'Rendition: the cover-up', the New Statesman published a confidential memo from the Foreign Office which suggested the steps which Blair could take to divert attention from the US practice of transporting Al-Qaeda suspects to interrogation centres.

A few days later Channel 4 News disclosed the contents of another leaked memo which gave an account of a discussion between the Prime Minister and the US President on 31 January 2003, six weeks before Iraq was attacked. The memo, obtained by Philippe Sands QC, Professor of Law at University College London and included in his book Lawless World, stated that Blair had said 'he was solidly with the President and ready to do whatever it took to disarm Saddam' despite the absence of a second UN resolution.

By far the most sensational leak of this period related to another of the Prime Minister's conversations with the US President, during which Bush was said to have suggested bombing the headquarters of the Arabic television station Aljazeera.

The first hint of the story that was about to break emerged on 17 November 2005, when the police revealed that a former civil servant and a political researcher had been charged with separate offences under the Official Secrets Act concerning the unauthorised disclosure between April and May 2004 of a confidential document relating to international relations. David Keogh, who had been a communications officer at the Cabinet Office, was accused of passing the document to Leo O'Connor, who at the time was political researcher for the Labour MP for Northampton South, Tony Clark

Five days after the two men were remanded on bail by Bow Street magistrates, the Daily Mirror claimed the leaked document was a five-page memo, stamped 'top secret', in which Bush told Blair that he planned to bomb Aljazeera's headquarters.

Scott McClellan, the White House spokesman, did his best to play down the story, insisting the Daily Mirror's claims were 'outlandish and inconceivable'; an anonymous Downing Street official suggested Bush's remark was simply a joke.

Whatever was being said publicly, the government's law officers responded with alacrity. Next day, in another front-page story, the Daily Mirror declared that it had been gagged by the Attorney General, Lord Goldsmith, who warned that 'publication of any further details from the document' would be a breach of the Official Secrets Act. Editors of other national newspapers were informed that they too would be liable to prosecution if they reproduced the contents of a document which had been 'unlawfully disclosed by a Crown servant'.

Opposition Mps and media lawyers claimed it was unprecedented for the press to be threatened with the Official Secrets Act when data alleged to have been obtained illicitly had already been published; injunctions against newspapers had previously been obtained by the Blair government but it had never prosecuted them for publishing leaked documents.

The Guardian concluded that the Attorney General had chosen to employ 'one of the most draconian pieces of legislation on the statute book' in order to put down a marker after so many previous leaks about the conduct of the war.

In response to the suspicion that it was the Prime Minister who was trying to gag the news media simply in order to avoid embarrassing Bush and to protect Downing Street's intimate relationship with the White House, Goldsmith insisted he was acting on his own initiative, in his independent role to 'protect the administration of justice', and his intention was to remind newspapers they needed to take legal advice; the secrecy laws were not being used to 'save the embarrassment of a politician'.

After a further court appearance on 10 January 2006 when the two men were committed for trial at the Old Bailey, Leo O'Connor's lawyer, Neil Clark, said that after reading the secret document he did not think it contained anything of embarrassment to the British government.

Mark Stephens, representing Aljazeera, added his voice to those demanding publication of the Bush-Blair conversation on the grounds that if there was any suggestion that the station's journalists could have been killed, that would amount to 'counselling and procuring a war crime'; in such circumstances, the Official Secrets Act could not be used to stop publication.

Nonetheless after a further court appearance in July 2006 in preparation for the start of the trial on 9 October, the Guardian reported that an Old Bailey judge, Mr Justice Aikens, had ruled that any discussion about the leaked transcript would have to take place behind closed doors; the public and news media would also be banned from hearing the prosecution's arguments on the grounds of national security.

The likely range of legal arguments which could be used in defending the two men was discussed in February 2006 at a rally organised by the Campaign for Press and Broadcasting Freedom. Mark Stephens thought David Keogh and Leo O'Connor, who had been charged with the 'unauthorised disclosure of a confidential document', would be well advised to follow the example of Katharine Gun and use the defence of necessity, especially as much of the trial might be held in secret.

'The only way to defend a case like this is to do what Katharine did and say this was a matter of conscience, that what was going on was a war crime; therefore take the moral high ground, just as Clive Ponting and others have done, and a jury will find for you'.

Gun, who also spoke at the rally, said she agreed with Stephens that the only way to stand up to the government was a for a whistleblower to argue that a leak was justified. In her case, once the government refused to publish the Attorney General's advice on the Iraq war, the prosecution had no alternative but to concede there were 'evidential deficiencies' which made it impossible to disprove her defence of necessity. Stephens was convinced the government would eventually have to publish the transcript despite what he claimed was Downing Street's determination to continue to filibuster and 'drag this out until the end of the Bush Presidency' in the hope that journalists would lose interest.

Running in tandem with disclosures exposing the secret manoeuvrings in advance of the military intervention in Iraq were unauthorised insights into the emergency measures designed the combat the 'war on terror' and the growing threat of terrorist attacks in Britain.

Bomb explosions on three London Underground trains and a bus on Thursday 7 July 2005, which claimed a total of fifty-two lives, followed by similar but unsuccessful suicide attacks on Thursday 21 July, added further volatility to an already unstable political environment.

The death of Jean Charles de Menezes, an innocent Brazilian suspected of being a suicide bomber, led to sustained speculation about a cover-up by the Metropolitan Police, an allegation which was suddenly given fresh impetus by a series of exclusive reports quoting documents leaked from the Independent Police Complaints Commission.

For several days during August 2005 the lead item in the bulletins of ITV News was scoop after scoop based on witness statements and the interim conclusions of the Commission's inquiry into the fatal shooting of de Menezes, which had occurred the day after the failed suicide attacks.

The leaks suggested that the Brazilian electrician was already being restrained by armed officers before he was shot seven times in the head and that he had not run away from the police by vaulting over a ticket barrier and entering Stockwell Underground station as originally stated; a leaked photograph showed a body on the floor of a tube train.

At the request of the Metropolitan Police, the Leicestershire constabulary was asked to conduct an inquiry and a month after the leak a woman employee of the Commission was arrested in connection with the unauthorised disclosure of IPCC documents to ITV News; several months later a television news producer was arrested on suspicion of theft together with another woman who had been arrested on suspicion of conspiracy to steal.

Nothing further was heard until May 2006 when the police announced that after discussion with the Crown Prosecution Service it had been decided there would be no charges against any of the three. CPS lawyers had advised that the IPCC employee could not be prosecuted for misconduct in a public office because it was doubtful that she was a public officer.

Once it was clear there would be no prosecutions, ITV News revealed the identity of the woman who supplied the documents. Lana Vandenberghe, a secretary at the IPCC, said she leaked the statements and photographs because she had been appalled by the failure of the Metropolitan Police to admit 'it was a lie' to suggest de Menezes had jumped over the ticket barrier to escape firearms officers.

She passed the information on to a friend whose partner was a news producer at ITV. 'When I first saw that story on the news that night, I thought "Oh my god, what have I done"'. She was suspended by the Commission; arrested; put in a cell and denied food for eight hours; and her flat was raided. 'The police attitude towards me was rude and bullying. They made it clear that I had done something wrong and that I could possibly be put in prison…But I would do it all again. I did the right thing. I helped the parents of Jean Charles and the public in finding out the truth'.

Neil Garrett, the ITV journalist who worked on the original story, told the Guardian how he obtained what turned out to be a sensational leak. 'My girlfriend, Louise, was at a barbecue with a friend who worked at the IPCC. Knowing that I was a producer for ITV news, the friend, Lana Vandenberghe, told Louise she had some information about what really happened the day Jean Charles was shot. It took another two weeks to get the full picture -- and when the ITV evening news on August 16 revealed the catastrophic failure of the surveillance operation it caused an absolute storm'.

Garrett conceded that the Police investigation into the leak had been thorough. 'But they just could not seem to countenance the idea that the only motivation was a desire on the part of our IPCC source to get the truth out. The only solace was that we hadn't been arrested under the Terrorism Act. One day in a police cell is bad enough, twenty-eight days must be a nightmare'.

Finally in July 2006 Lana Vandenberghe met three members of the de Menezes family and subsequently she wrote about her experience in the Guardian. After being plagued with negative memories about her decision to speak out, she felt so much better once she discovered how important it had been to the family to help them learn the truth about what happened to Jean Charles.

'It's extraordinary that this man who I never met has had such an impact on my life. I spoke out for him and his family, to make sure the truth wasn't covered up. I don't see myself as brave for doing that. I know if my grandmother, who always spoke her mind, were still alive, she'd be proud of me for what I did'.

Trading Information: Leaks, lies and tip-offs by Nicholas Jones (Politico's July 2006).