David Cameron has been accused of "manipulating" the former head of MI5 into warning that Britain's national security would be put at risk by a Brexit.

Lord Evans, a former director of MI5 and Sir John Sawers, a former head of MI6, said in a joint article that a Brexit would hamper 'our ability to protect ourselves from terrorists'.

However Julian Lewis, the Conservative head of the defence select committee, said that Lord Evans had told him privately that leaving the EU would "make no difference" to national security.