The case, which has reopened the debate on the Act in Britain, may also become a cause celebre in French and European law. At his hearing in Paris yesterday the French state and Mr Shayler's lawyers argued that the decision on whether to return him to Britain could have an important impact on future judicial relations between EU countries.
The Chambre d'Accusations must decide in the next four weeks whether Mr Shayler committed a "political" crime and whether the concept of "political crime" still exists between EU nations.
In a statement Mr Shayler said: "The only thing I have ever done ... is to criticise the [British] state." His motive in leaking MI5 secrets to the press was to expose the shortcomings of the security services. He denied an accusation by the French public prosecutor that he had sold the information simply to make money. He had accepted pounds 20,000 from the Mail on Sunday because he knew he would have to flee abroad and would need cash to survive. He had offered to return the money.
Mr Shayler, 32, a junior officer in MI5, was arrested in Paris in August at the request of British police. He is charged with a breach of the Official Secrets Act after leaking 30 top-secret documents which were the basis of a Mail on Sunday article on bungling, incompetence and persistent drunkenness in MI5.
France does not extradite people for "political crimes" but a 1996 European convention committed EU countries to abolish the concept of "political" crime. France's constitutional council ruled that the treaty infringed a "fundamental principle" of French law and could not be ratified. Mr Shayler's lawyer, William Bourdon, said the British police had admitted no vital state or defence secret had been threatened. By negotiating a possible deal or amnesty with Mr Shayler they admitted in effect that his case was a political, not a criminal one.
MI5 files on Labour front- benchers were handed to Tony Blair by the security-service head as he prepared to form his Cabinet, it was disclosed yesterday, writes Colin Brown.
The report by the Intelligence and Security Committee does not identify the ministers, but Jack Straw, Home Secretary, and Peter Mandelson, Secretary of State for Trade and Industry, are known to be among ministers with security-service files on their past as student activists.
Mr Blair is expected to respond to the report next week by accepting a key recommendation to allow the committee to appoint a Whitehall "spywatcher" to reinforce its checks on Britain's intelligence services. Its chairman, Tom King, a former Tory minister, said the "spywatcher" would investigate cases at the request of the committee and have access to all relevant documents. The "spywatcher" would check the veracity of information given to the MPs by the security and intelligence services.