Boris Johnson has insisted he will not leave No 10 despite a mounting revolt against his leadership.

Ministers and aides have continued to submit their resignations, while support is ebbing away from the Prime Minister among previously-loyal MPs.

But Mr Johnson is understood to have told allies that he is “not going anywhere” and his critics should “calm down”.

On Wednesday morning, Robin Walker resigned as schools standards minister, telling the Prime Minister the “great achievements” of the Government have become “overshadowed by mistakes and questions about integrity”.

Will Quince quit as children and families minister, saying he could not accept being sent out to defend the Prime Minister on television with inaccurate information over the Chris Pincher row.

Treasury economic secretary John Glen quit, telling the Prime Minister he could not reconcile staying in the job with “the complete lack of confidence I have in your continuing leadership of our country”.

Victoria Atkins resigned as a minister in the Ministry of Justice, telling Mr Johnson: “I can no longer pirouette around our fractured values. We can and must do better than this.”

Laura Trott resigned as a ministerial aide, saying “trust in politics is – and must always be – of the utmost importance, but sadly in recent months this has been lost”, while Felicity Buchan also stood down as a parliamentary private secretary, calling for “fresh leadership”.

Their resignations followed a string of departures from the Government on Tuesday evening, led by Rishi Sunak and Sajid Javid, who delivered broadsides at Mr Johnson as they quit their Cabinet posts.

Former health secretary Mr Javid is expected to add to Mr Johnson’s problems with a personal statement in the Commons on Wednesday.

This will come after the Conservative leader faces a potentially difficult session of Prime Minister’s Questions, while he will also have to endure a grilling by the Liaison Committee of select committee chairmen and women – including some senior Tory critics.

Education Select Committee chairman Rob Halfon, one of those who will question the Prime Minister, said he would back a change in leadership, criticising not only a “real loss of integrity” but also “a failure of policy”.

But Mr Johnson told friends he will continue to “smash on and deliver for the people who gave us a massive mandate”, the Daily Mail reported.

“Everyone just needs to calm down, stop bickering and let us get on with the job in hand.”

New Chancellor Nadhim Zahawi hinted at reversing a planned rise in corporation tax as part of the effort to win over Tory MPs.

But the Cabinet reshuffle does not appear to have persuaded Mr Johnson’s critics to hold fire.

Mr Quince was one of the ministers sent on the airwaves to defend Mr Johnson’s position over Chris Pincher, who quit as deputy chief whip after allegedly assaulting two men while drunk at London’s Carlton Club.

The Prime Minister later acknowledged he had previously been informed of allegations against Mr Pincher dating back to 2019 and said he regretted keeping him in government beyond that point.

Mr Quince said he had received a “sincere apology” from Mr Johnson for being sent out with an “inaccurate” briefing about the Prime Minister’s knowledge of events.

But “I have no choice but to tender my resignation” as “I accepted and repeated those assurances in good faith”.

Mr Walker’s resignation letter to the Prime Minister said: “Recent events have made it clear to me that our great party, for which I have campaigned all of my adult life, has become distracted from its core missions by a relentless focus on questions over leadership.”

He added: “I have always believed it is the job of our party to strike the right balance between efficiency and compassion, but the image being projected from the struggles of the last few months is that we risk achieving neither.”

The Prime Minister’s authority had already been damaged by a confidence vote which saw 41% of his own MPs withdraw their support in June.

The loss of crunch by-elections in Wakefield and Tiverton and Honiton later that month triggered the resignation of party chairman Oliver Dowden, while there is still lingering anger over coronavirus lockdown-busting parties in Downing Street.

Tory MPs are also uneasy about the Government’s high-spending, high-taxing approach as a result of the response to the pandemic.

Mr Zahawi sought to reassure Conservatives that “nothing is off the table” when questioned about possibly scrapping the planned increase in corporation tax from 19% to 25% in April 2023.

“I will look at everything. There’s nothing off the table. I want to be one of the most competitive countries in the world for investment,” he told Sky News.

“I know that boards around the world, when they make investment decisions, they’re long term, and the one tax they can compare globally is corporation tax. I want to make sure that we are as competitive as we can be whilst maintaining fiscal discipline.”

The Prime Minister’s fate may ultimately lie with backbench MPs if the Tory 1922 Committee’s rules are changed to allow another confidence vote within 12 months.

Elections to the committee’s ruling executive are expected next week, which could then lead to a decision on changing the rules.

West Dorset MP Chris Loder told BBC Radio 4’s Today programme: “I think he does need to go.

“I think if he chooses not to, I think the 1922 Committee should act and I certainly would support that approach in the forthcoming 1922 elections.”

Lee Anderson, one of the MPs elected in 2019 in Red Wall seats who largely owe their political careers to the Prime Minister, said he too had lost faith in the leader.

The Ashfield MP pointed to the row over Mr Pincher’s appointment and said: “Integrity should always come first and sadly this has not been the case over the past few days.”