Penny Mordaunt

Age: 45

Odds: 20/1

Brexit pitch: The International Development Secretary is a rising star. Since her election in 2010 she has risen steadily up the ranks, and has impressed with her handling of the scandals that have beset the charity sector.

In a recent article, she claimed that voters were suffering as a result of a lack of leadership in Westminster and called for radical change, in a polemic seen by many Tory activists as a leadership pitch to the party faithful.

However, her reluctance to come out one way or the other on Mrs May’s deal has caused consternation among Brexiteers, who have begun to question whether she is up to the task.

Whilst a number of potential leadership rivals have a clearly established policy agenda, there are few in Westminster who know what Ms Mordaunt stands for beyond Brexit.

Having sat on the fence as opposition to Mrs May’s deal grew, she may find herself struggling to establish a firm base of support when the time comes.