A former British spy is asking Britain's Supreme Court to overturn a decision by domestic intelligence agency MI5 to block him from publishing a book about his career.
Lawyers for the former MI5 officer, who is not named in court documents, told a hearing Monday that he is seeking a judicial review of the decision.
Britain's government says publishing the book could threaten national security.
In a famous case in 1998, Britain's government lost a three-year campaign to ban publication of "Spycatcher," a memoir by ex-MI5 officer Peter Wright.
Former MI5 chief Stella Rimmington published an autobiography in 2001, after the government censored some sections and said it regretted and disapproved of her decision to write the book.
