British Prime Minister David Cameron was expected on September 1 to outline tougher measures against Britons suspected of joining jihadists in Syria and Iraq.
Cameron’s statement to the House of Commons comes after Britain raised its terrorist threat alert on August 29, saying an attack planned by British jihadists in Syria or Iraq was "highly likely.”
Cameron was expected to propose fresh steps against suspects when there is insufficient evidence to charge them with a crime.
British media reports said the measures could include a "temporary bar" on the return of Britons who are suspected of fighting abroad as members of Islamic militant groups.
Concerns about attacks in Britain by returning British jihadists were raised last month by the beheading in Syria of U.S. journalist James Foley, apparently by a British member of Islamic State.