A vote of confidence in the Tory Party leader has been called, and he will now have to win a vote of the other Conservative MPs to stay in charge.

If more than 50% of them think he should stay in charge then Duncan Smith stays as leader, if not, a new leader will be chosen in a later vote.

The vote is happening because 25 Tory MPs have written to say they want one.

If Duncan Smith loses the vote of confidence, to be held on Wednesday, there would then be another vote to decide who would replace him.