Sunak and Truss win split Cabinet backing, as Patel rules out bid for No 10

But the former chancellor who helped force Mr Johnson’s downfall received backing from Deputy Prime Minister Dominic Raab and Transport Secretary Grant Shapps, after he pulled out of the Tory leadership contest.

Mr Shapps was struggling to win the support of the 20 Conservative MPs required to pass the first hurdle by the 6pm deadline, while Home Secretary Ms Patel said she would not be running.

Education Secretary James Cleverly also came out in support of Ms Truss, who is seen as a “stop Sunak” candidate by some on the Tory right who are angered by his high-tax, high-spend policy during the pandemic.

Launching his campaign, Mr Sunak pledged to cut taxes only when inflation is under control as he called for a “return to traditional Conservative economic values” in criticising rivals’ “fairytales” about immediate tax cuts.

Brexit opportunity minister Mr Rees-Mogg backed Ms Truss for “always opposed Rishi’s higher taxes”, in efforts he labelled “proper conservativism”, after he left a meeting of Mr Johnson’s Cabinet.

By his side in Downing Street, Culture Secretary Ms Dorries told reporters Ms Truss, who voted Remain in the 2016 referendum, is probably a “stronger Brexiteer than both of us” and has “consistently argued for low tax policies”.

Other developments in another hectic day in Westminster included:

– Former equalities minister Kemi Badenoch launching her bid, vowing not to enter a tax cut “bidding war” and arguing others had been trying to “have your cake and eat it”.

– Senior backbencher Tom Tugendhat promising to slash fuel duty by 10p as he kicked off his campaign, dismissing rivals’ criticism over his lack of ministerial experience.

– Jeremy Hunt pledging to cancel “unthinkable” planned cuts to the size of the Army in the face of Vladimir Putin’s threat and raise defence spending to 3% of national income by 2028.

– Chancellor Nadhim Zahawi brushing off a rebuke from Bank of England governor Andrew Bailey for setting out tax proposals during the campaign, saying he was setting out his stall to be the next prime minister and his plans were “fully costed”.

After being welcomed to stage as a “true Conservative” by Mr Raab, Mr Sunak told his launch that tax cuts are “a question of when, not if”.

He argued it is “not credible to promise lots more spending and lower taxes”, in a swipe at rivals who have proposed multibillion-pound tax cuts immediately.

Instead Mr Sunak, widely seen as one of the frontrunners, said he would only cut taxes “once we’ve gripped inflation”.

“We need a return to traditional Conservative economic values and that means honesty and responsibility, not fairytales,” he said.

Mr Sunak acknowledged he had “frequently” disagreed with Mr Johnson but said he would not “demonise” the man expected to remain in Downing Street until after a successor is announced on September 5.

Leadership rival Mr Zahawi, the current Chancellor, criticised his predecessor’s hesitancy, insisting it is not a “fairytale” to cut taxes to ease the cost-of-living crisis.

By Tuesday morning, trade minister Penny Mordaunt and Mr Sunak looked to have the declared backers to make the threshold for the next stage under the newly-hastened timeline, while Mr Tugendhat’s nomination papers were the first to be submitted shortly after the process began at 3pm.

Several others, Mr Zahawi, Mr Hunt and Ms Badenoch, were close enough before nominations formally opened to suggest they will be in the race.

Struggling to make the cut, Mr Shapps pulled out to support Mr Sunak, arguing he “has the competence and experience to lead this country”.

But Mr Shapps’ switch inadvertently aided Ms Truss by taking her tally of publicly-declared declarations past the threshold, when backbencher Paul Bristow switched his allegiance to her.

Ms Patel did not give a reason why she was pulling out, nor did she name a favoured candidate, but there had been warnings over the right-wing vote being split.

She said she was “grateful for the encouragement and support” from colleagues and Tory members who she said had encouraged her to enter the race.

But she added: “I will not be putting my name forward for the ballot of MPs.

“Like all Conservative MPs and party members, I will be listening to cases being put forward by the candidates standing for the leadership of the party, and trust the contest will be conducted…