DAVID Cameron is considering a temporary ban on British jihadists returning from Syria and Iraq.

The Prime Minister is thrashing out a new package of anti-terror measures with his Liberal Democrat deputy Nick Clegg ahead of today's Commons statement. However, Sir Menzies Campbell MP warned any such move could be ­illegal under international law.

After Britain's terror threat level was raised from substantial to severe, another former LibDem leader, Lord Ashdown, accused ministers of "kneejerk" reactions.

Defence Secretary Michael Fallon said: "We have had Tube trains blown up, London buses, Glasgow Airport attacked, a soldier murdered in broad daylight. These are very real threats we are dealing with. This isn't any kind of knee-jerk response. We've had a number of young men going off to fight in Syria, a number of them slipping back home again. We need to make sure that, where we can, we plug those existing gaps."