Allies of Theresa May have claimed the plot to oust her from Number 10 is set to “fizzle out” after former Conservative Party chairman Grant Shapps was identified as the ringleader.

Mr Shapps insisted there was growing support among a “broad spread” of Tory MPs for a leadership contest in the wake of the Prime Minister’s chaotic party conference speech.

But Charles Walker, vice chairman of the powerful Conservative backbench 1922 Committee, said the attempt to force her out lacked credibility and was set to fail.

“Number 10 must be delighted to learn that it is Grant Shapps leading this alleged coup,” he told the BBC.

“Grant has many talents but the one thing he doesn’t have is a following in the party. I really think this is now just going to fizzle out.

“What you are seeing here is probably the coalition of disappointed people who think their brilliant political talents have not been fully recognised.”

Mr Shapps was named by the Times as the leader of a group of around 30 Tory MPs planning to send a delegation to Mrs May to tell her she must go.

He accused the party whips of deliberately leaking his name to the newspaper in an attempt to “smoke out” the rebels.

The plan, he said, had been for a group – including five ex-Cabinet ministers – to approach Mrs May in private with a list of names to avoid the “embarrassment” of a formal leadership challenge.

But those loyal to the Prime Minister said it was clear that the rebels lacked the 48 MPs they needed to force a contest under the party rules.

Mr Shapps said support for a leadership election was growing, with some current Cabinet ministers privately signalling their support.

“They are Remainers, they are Brexiteers,” he told BBC Radio 4’s Today programme.

“A growing number of number of my colleagues, we realise that the solution isn’t to bury our heads in the sand and just hope things will get better. It never worked out for Brown or Major and I don’t think it is going to work out here either.”

He acknowledged, however, that they could not force the Prime Minister’s hand and that it was up to her to decide whether she wanted to carry on.

Shoertest-servings prime ministers of the past 100 year(PA graphic)

“It will have to be her decision. I had rather hoped that we would be able to get to point where we could go to her privately and have this conversation, I am very sorry that the whips have not made this possible,” he said.

He added: “I am slightly surprised that the whips decided to brief a newspaper about it. That was their idea to smoke people out,”

Senior ministers, meanwhile, continued to rally round Mrs May, with Environment Secretary Michael Gove – who ran against her in last year’s leadership contest – saying she was doing a “fantastic job”.

He said the “overwhelming majority” of Tory MPs – including the “entirety” of the Cabinet – wanted her to carry on.

“She showed an amazing degree of resilience and courage this week, of a piece with the fantastic leadership she has shown through the time that she has been Prime Minister,” he told the Today programme.

“The truth is that the overwhelming majority of people want the Prime Minister to concentrate on doing the job which 14 million people elected her to do earlier this year.

“I think it would be disrespectful to those 14 million people to do anything other than concentrate on those areas where action is necessary.”