However, in an interview with The Telegraph, Ms Rudd said Mr Johnson was not offended and they get on well.

“Sure, I like him yeah. To be brutal I like most of my colleagues. I am not somebody who actually fights. I get on perfectly well with him.”

She will not comment on the future but says: “I have worked with him before. He was Foreign Secretary, I was Home Secretary. We were able to work together.”

For the first time Ms Rudd rules herself out of standing to be leader – a month after saying the door was “slightly ajar” to her standing.

She says: “I am conscious that the Conservative party wants to have someone who they believe is very enthusiastic about Brexit.

“I still think it is a difficult job to do but we can do it, we can make a success of it.

“There are all sorts of plans I would like to have when we do leave the European Union but I don’t think it is my time at the moment.”

Mr Rudd will not say who she backs until her newly launched One Nation group of 70 Conservative MPs has held its own leadership hustings of the main candidates.

She says: “We want to hold back before committing anybody because we want to interrogate them on the policies.”

Ms Rudd is applying these One Nation principles to her department: from next week 250,000 disabled pensioners will no longer have to undergo checks to receive benefit payments.

Ms Rudd , 55, credits the move with her experience of looking after her father Tony who was blind for 36 years until his death in 2017.

She says: “I know how vulnerable disabled people are - but particularly elderly disabled people. He was amazingly strong and robust. We used to read the Telegraph to him often.