His attempt to make peace with the UK and find an amicable settlement with his former employers has been rebuffed by government lawyers.

And it may be many years - if ever - before he is allowed back into the UK without being arrested for alleging, among other things, an MI5 plot to kill Colonel Gadaffi.

Mr Shayler denies he is a traitor, claiming instead he is just blowing the whistle on inefficiency and bureaucracy in the Secret Services.

But things are about to swing dramatically in favour of whistleblowers.

UK in front

The irony is that while the UK is acting against Mr Shayler, it is about to introduce what has been described as the world's most far-reaching legal protection for whistle-blowers.

Next month, the Public Interest Disclosure Act will come into effect. Unusually for the UK, which normally comes in for criticism for being obsessed with secrecy, the protection is much wider than in many other countries, including America.

Key elements of the new law:

• For a start, it will apply to workers in any industry, not just the public sector.
• It will protect workers who raise genuine concerns about crimes, illegality (including negligence), miscarriages of justice, danger to health and safety or the environment, and about the cover-up of such incidents.
• Workers can make disclosures to internal bodies, or to regulatory bodies such as the Health and Safety Executive,
• If a worker thinks they will be victimised for making such a disclosure, or if the matter is exceptionally serious, they can tell the police, MPs or the media.

The Herald of Free Enterprise

The passing of the law had been "unbelievably fortunate", Mr Dehn said. It had started as a private member's bill introduced by libertarian Conservative MP Richard Shepherd, and attracted government and opposition support. "It must have been a whole sequence of stars and planets in happy alignment."

No gags

The law also deals with cases where employers put "gagging clauses" on former workers as part of a pay-off deal. People who have left their job in these circumstances will be free to disclose wrongdoing without jeopardising their settlement.

It also introduces a public interest defence for people facing disciplinary action under the Official Secrets Act.

Richard Shepherd MP: "this marks an irreversible shift away from secrecy"

It has been predicted that if the new law works properly, many of the horrendous accidents which have happened over the last few years could have been averted.

For instance, an inquiry into the 1987 sinking of the Herald of Free Enterprise outside Zeebrugge harbour found that workers had warned five times of their concerns about the bow doors being left open. The warnings were not heeded, and 193 people died.

Speak up

The thinking goes that this and other incidents including the Clapham rail crash, the spread of BSE among cattle, even the collapse of Barings Bank, could have been prevented if people had felt more confident about publicly voicing their worries.

The Department of Trade and Industry is expected to inform employers and workers of the new laws early in the New Year.

Just in case employers should think the new legislation is hostile to them, they should consider this: whistleblowing can be good for their wealth.

A report by the Audit Commission published last month urged local authorities to establish systems for would-be whistleblowers to come forward. One council discovered that it had lost £750,000 through "ghost pensioners" - 18 fictional former employees who were collecting pensions despite not existing. The scam was brought to light by a whistleblower.