Boris Johnson is facing a revolt from scores of his own backbenchers as they line up to condemn the Prime Minister and his chief adviser Dominic Cummings.

A storm of protest continues to rage not only over revelations that Mr Cummings broke the Government’s own lockdown guidelines, but also over Mr Johnson’s defence of him on Sunday.

At least 15 Conservative backbenchers have called for Mr Cummings to go, while several others have spoken out against his actions.

Newly elected MPs including Elliot Colburn, Paul Holmes and Jonathan Gullis have said they have “conveyed the strength of local feeling to relevant colleagues” after being contacted by constituents.

Conservative former minister Paul Maynard said he shared people’s “dismay” at the PM’s response, and was one of many MPs who insisted Mr Cummings should quit or be sacked.

“It is a classic case of ‘do as I say, not as I do’ – and it is not as if he was unfamiliar with guidance he himself helped draw up,” he said.

“It seems to me to be utterly indefensible and his position wholly untenable.”

Veteran Conservative Sir Roger Gale told the PA news agency: “I’m very disappointed, I think it was an opportunity to put this to bed and I fear that now the story is simply going to run and run.”

Any residual hope that this might die away in the next 24 hours is lost

Senior Tory MP Simon Hoare, who had already called for Mr Cummings to go, later criticised Mr Johnson’s press conference, telling the Daily Mail: “The PM’s performance posed more questions than it answered.

“Any residual hope that this might die away in the next 24 hours is lost.”

Somerton and Frome MP David Warburton said Mr Cummings was “damaging the Government and the country that he’s supposed to be serving”.

Speaking on BBC Breakfast on Monday morning, he said his own father had died alone as a result of the coronavirus lockdown.

“People have made sacrifices, this is a difficult time, this is a time of national crisis,” he said.

“In those sacrifices there really hasn’t been the choice to use instinct. Instinct hasn’t really been part of it. We’ve been tasked with following regulations laid down by the Government.”

Tory grandee Lord Heseltine said it was “very difficult to believe there isn’t a substance” in the allegations about Mr Cummings’ movements.

“I think these unanswered questions are now on the agenda,” he told the BBC, “and I don’t think that this anxiety about the Government’s position will end until we know the whole story.”

Another Tory MP, Jason McCartney, said while it was important for people to show compassion during the crisis, Mr Cummings had to go because the “perceived hypocrisy of the rule makers potentially threatens the success of any future measures” under any second wave of the coronavirus.

“We must have confidence that we are doing the right things for the right reasons and that we are all truly in it together. For that reason I believe Mr Cummings’ position is now untenable,” Mr McCartney said in a Facebook post.

Drawing attention to “the moral hazard of Cummingsgate”, Tory MP George Freeman retweeted an article from The Spectator which said Mr Johnson’s judgment was “now the issue”.

East Worthing & Shoreham MP Tim Loughton said he had “come to the conclusion that the position of Dominic Cummings is untenable as the chief adviser to the Government and he must resign or be removed”.

Former minister Steve Baker said if Mr Cummings does not resign “we’ll just keep burning through Boris’s political capital at a rate we can ill afford in the midst of this crisis”.

Other critics include Peter Aldous, Peter Bone, Damian Collins, Caroline Nokes, Julian Sturdy, Robert Syms, Craig Whittaker, James Gray and Martin Vickers.

Opposition parties have also been fiercely critical.

Labour leader Sir Keir Starmer said Mr Johnson had failed a test of leadership, adding that his decision to take no action against Mr Cummings was “an insult to sacrifices made by the British people”.

Acting Liberal Democrat leader Ed Davey tweeted “Cummings must go”, saying the public would be “confused and angry” that he is still in his position.

Scottish First Minister Nicola Sturgeon accused Mr Johnson of jeopardising public health messaging by backing Mr Cummings.

However, the PM won support from some in his party.

MP Lee Anderson said he was “disgusted” by the treatment of Mr Cummings by the media and some online commentators.

In a post on his Facebook page, the MP for Ashfield in Nottinghamshire wrote: “I have received messages and emails about Dominic Cummings. I have lots of questions to be answered before I pass judgement or comment.

“I will not accept trial by media when a persons whole future is at stake. The reaction of the press outside his home and some online comments have quite frankly disgusted me. I have been on the receiving end from the media in the past and it has an awful impact on members of your family.”