Sir Malcolm Rifkind is to quit as an MP at the general election amid fresh pressure over cash-for-access allegations following an undercover sting.

The Tory former foreign secretary said he had also stepped aside as chair of the parliamentary Intelligence and Security Committee.

The veteran politician said the allegations against him were ''contemptible'' but that it was better for the party and his Kensington constituency if he did not seek to stand in 2015.

He yesterday had the party whip suspended pending an internal investigation as to whether he should remain the candidate for May's poll.

''I had intended to seek one further term as MP for Kensington, before retiring from the House of Commons,'' he said in a statement.

''I have concluded that to end the uncertainty it would be preferable, instead, to step down at the end of this Parliament.

''This is entirely my personal decision. I have had no such requests from my constituency association but I believe that it is the right and proper action to take.

''As regards the allegations of Channel 4 and the Daily Telegraph I find them contemptible and will not comment further at this time.

''Although I will retire from Parliament I shall continue my public and political life and am much looking forward to doing so over the years to come.''