Hastings and Rye MP Amber Rudd has backed Jeremy Hunt to be the next leader of the Conservative Party.
Theresa May has stepped down as the party’s leader but will remain as Prime Minister until her successor is chosen.
Foreign Secretary Jeremy Hunt is one of 11 candidates currently in the running.
Ms Rudd, who is work and pensions secretary, gave her backing to Mr Hunt in an article in The Times, saying he ‘stands out above everyone’.
She wrote: “A new prime minister has a new opportunity. I know that the EU is ready to engage with a new leader if they come with a credible plan to break the impasse and with the right human touch and spirit.
“It is not enough to be told to shut your eyes, cross your fingers, pick up some magic beans and believe in Britain. We need a skilled negotiator and deal-maker, not an instruction for more optimism.
“These are serious times. They require a serious leader who will be listened to in Brussels. Jeremy Hunt is that leader and I am deeply proud to support him.”
She went on to describe how when she was first selected in 2006 as the Conservative candidate for Hastings and Rye, Mr Hunt was appointed her mentor and was an ‘invaluable source of knowledge and encouragement.’.
The endorsement will be seen as an important one in Westminster circles as Ms Rudd is co-leader of the ‘One Nation’ Conservative group.
Later speaking to the Today programme on BBC Radio 4, she described how she had considered backing Boris Johnson.
She explained: “There are many great things about Boris, but my concern is who is going to actually think carefully about how to break this impasse and to me it’s not enough to say: ‘We’re definitely leaving by October 31st’ without addressing how you are going to resolve it.”
Asked about environment secretary Michael Gove’s admission he had used cocaine two decades ago, Ms Rudd said: “I know Michael, he is a good and honourable person and I hope that comes through in this leadership contest.”
But Ms Rudd said she had spoken to him about it and if and when he became Prime Minister there would be no changes and this was simply a personal view.
Candidates have until 5pm today to submit their nomination papers, which must be supported by at least eight MPs.
MPs will whittle down the candidates to the final two, with ordinary Conservative Party members then having the final say.