On The Run is the working title of Shayler's account as a spy and a fugitive, said the paper. Shayler was released from jail in Paris on November 18 when the appeals court turned down Britain's request for his extradition. He wrote the book while in prison. London is reportedly worried that his memoirs might disclose secret operations.Among his allegations are that Britain tried to assassinate Libyan leader Muammar Gaddafi.

Government lawyers have written to 20 publishers warning them not to release the book, said The Sunday Times. Shayler, however, insisted to the paper that his memoirs did not compromise national security. ``It is about living life on the run,'' he said. ``It is the story of the story.''

The 32-year-old was arrested in France last August after 10 monthson the run. He was wanted for disclosing government intelligence, but the Paris appeals court opposed his extradition because the charges laid against him were `political under French law'.

The Paris prosecutor's office has lodged a further appeal against the ruling.

Shayler, 32, fled to France in 1997 after claiming that MI5, Britain's internal security agency, held files on more than 500,000 British subjects, including at least two ministers in the present government.

Britain wanted him placed on trial under the Official Secrets Act for disclosing details about British intelligence operations. Shayler worked for MI5 from November 11, 1991, to October 4, 1996.

Britain has unsuccessfully fought publication of ex-spies' memoirs before, most famously in Australia over former agent Peter Wright's Spycatcher.