A law to silence whistle-blowers: Serious journalism has been fettered by the fining of Channel 4 for protecting an anonymous source, says Liz Forgan

'The companies would say that 'A' would never have co-operated but for the undertakings, and without his co-operation there would have been no programme. As it was in the public interest the programme be broadcast, so the public interest required them to give the undertaking. However, this in law is an impermissible approach.'

So Lord Justice Woolf last week found Channel 4 and Box Productions guilty of contempt of court for refusing to identify their anonymous source, 'A', in the Dispatches programme about collusion between security forces and paramilitaries in Northern Ireland.

His words torpedo the basic public-interest argument for any journalist, print or broadcast, being able to promise a source that his or her identity will be kept secret. Without that promise a small but extremely important category of journalism becomes impossible in Britain. And the worst of it is that the judgment came from one of the most fair-minded, clear- thinking and respected figures on the bench.

The gulf between how the serious press and the other three estates of the realm see the public interest could not have been spelt out with more devastating lucidity.

'To contend that . . . a journalist or anyone else has a right to conscientious objection which entitles him to set himself above the law if he does not agree with the court's decision is a doctrine which directly undermines the rule of law and is wholly unacceptable in a democratic society,' Lord Justice Woolf said.

C 4 should have known that 'there was at least a substantial risk of an order being made'. Given that risk, he said, it could not promise anonymity. The dilemma it found itself in - whether to honour its undertaking and protect the life and identity of its source, or comply with the court's order - was 'a dilemma of their own making'.

Lord Justice Woolf recognised that what he was saying presented a serious problem. He attempted to suggest a remedy. But what he said only demonstrated further the gulf of incomprehension between the two sides. If a source required anonymity, he said, journalists should offer a conditional guarantee - to be held to unless a court required it to be breached. Tell that to a man in fear of his life - or of losing his livelihood, being ostracised, sent for psychiatric treatment or any of the other disasters that can befall a whistle-blower.

Alternatively, he said, C 4 could have 'sought advice at the highest level of government . . . as to the propriety of the action they were proposing', presumably with an eye to indemnity from prosecution if the appropriate official agreed with the thrust of the programme.

But what if it were the behaviour of a government agency that a journalist was seeking to expose? And since any guarantee has to be given before the witness tells his story, let alone before it can be checked, it is hard to see how any government figure could take the proposition seriously.

The puzzle is why intelligent, honourable people take such opposite views. Journalists do not seek to be above the law, but there is a public interest in exposing iniquity. We know that there are people who feel - for whatever reason - that they cannot take their evidence openly to the authorities. Instead they take it covertly to the media. How can it be in the public interest to make that impossible?

There is a shocking list of miscarriages of justice and misdemeanours by public authorities: the Guildford Four, the Birmingham Six, the Maguire family, Rampton, Broadmoor, Cathy Massiter, case after case in the Rough Justice series; and only this week, Ty Mawr and Ashworth. In all these cases the media's role in exposing the truth was crucial.

There are dangers in using anonymous information. Because it cannot be challenged in the normal way, there is an inherent risk of false accusation. No case that relies substantially on anonymous evidence can ever be conclusive (as we have acknowledged in the Dispatches case). Anonymous sources are deeply unwelcome, but sometimes they are the only witnesses to events which the public ought to know about.

The label of journalism is sometimes used to justify indefensible activities. Even the brightest and best can confuse their own vanity or profit with the public interest. Accused people should not be tried on television, but in proper courts with proper rules of evidence. The rule of law is a guarantee of democracy. But good journalism is also fundamental in a free society, and should not need defending as much as it currently seems to do.

Certainly the courts must decide where the public interest lies. Journalists who cannot accept their verdicts must expect to pay a price. The problem arises over the context in which judges make those decisions and the scale of the penalties.

There is no statutory protection for freedom of information in Britain. We have not incorporated the European Convention on Human Rights into British law. Section 17 of the Prevention of Terrorism Act (used for the first time in the C 4 case to attempt to force journalists to reveal sources) provides no appeal against the decision of a Crown Court judge making an order of such importance.

The fines available are unlimited, and could, if the Director of Public Prosecutions had had her way, have resulted in the closure of a national broadcaster. Not for lying, cheating, invading privacy or harming innocent children, but for pursuing a difficult, unpopular but important story.

We need a law that expressly acknowledges the role of unfettered journalism in our society. The courts should be required to weigh motive and morality when considering the scale of penalty, instead of individual judges being free to impose unlimited fines for any breach of a court order. And there should be a proper system of appeal against an order made in a lower court which runs so powerfully to the heart of fundamental freedoms.

The author is Channel 4's director of programmes.