He warned efforts to influence the result by running weaker candidates against a preferred frontrunner often backfired with the poorer performers coming out ahead, but said “wild horses on bended knees” would not convince him to reveal which colleagues he might have in mind.

Sir Eric, 65, was educated in Keighley in his native Yorkshire, and served on Bradford Council before becoming an MP in 1992.

He served as Chairman of the conservative Party from January 2009 to May 2010, when he was made Secretary of State for Communities and Local Government in the coalition government led by David Cameron. He was replaced by Greg Clark in May 2015.

This morning he said: “I think it’s better to go while people are asking ‘why are you going?’, rather than when they’re saying ‘why the hell is he still there?’

“And at 65 you’ve got a chance to do something else.”

He will continue in his role as the UK’s special envoy for Post-Holocaust Issues, a role he said he feels passionately about and which he foresees will keep him busy, especially in the area of the repatriation of Nazi-plundered valuables and works of art.

He predicted a “well-deserved majority” for the Prime Minister in the forthcoming election, but added: “If I were to offer some advice to my fellow Conservatives: take nothing for granted.”