A Cabinet ally of Boris Johnson said there was a “very well-organised” campaign to oust him despite a lack of evidence for the claim.

Culture Secretary Nadine Dorries said anyone denying a co-ordinated plot was “not telling you the truth”.

But Sir Graham Brady, chairman of the backbench 1922 Committee which oversees the confidence vote process, said he was “not aware of any orchestrated campaign”.

Ms Dorries told Sky News: “Anyone who says that this isn’t being co-ordinated and isn’t being organised behind the scenes, I’m afraid, is not telling you the truth.

“This is a very well-organised campaign.

“It’s a perfect storm for some – it’s Remainers who are taking in others who are disaffected and, for a number of reasons, those who who’ve lost their jobs in cabinet or as ministers, and I’m afraid anyone who says that this isn’t organised is not telling you the truth.

“It is a very well-organised campaign by a small number of individuals, some who believe that they should be the next prime minister.”

Asked which individuals, she said: “I’m not going to say but it’s a small number of individuals who’ve organised and whipped up this storm, and I’m afraid we’re going to reach a point where people aren’t going to vote for the Conservative Party because people don’t vote for divided parties.

“So, we need to get this vote over and done with, and those MPs need to hear a clear message.”