The culture secretary, Nadine Dorries, has rejected calls for Boris Johnson to resign in order to restore trust after the “partygate” scandal, claiming that the “vast majority” of the party were behind the prime minister. It comes after the former schools minister, Nick Gibb, became the latest Conservative MP to publicly call for Johnson to go, citing constituents “furious about the double standards” and the prime minster’s “inaccurate” statements in the Commons. It also follows reports that the Metropolitan police, which was given 300 pictures by Sue Gray for its investigation into Covid rule-breaking social gatherings, has a photograph of Johnson holding a can of beer at his lockdown birthday party in June 2020. According to the Mirror, the prime minister is pictured with a can of Estrella while standing next to the chancellor, Rishi Sunak, in No 10’s Cabinet Room. The newspaper reported that the picture was taken by Johnson’s official photographer, funded by the taxpayer, who was documenting the event. Dorries said on Saturday that the Conservative expressions of dissent, including from Gibb, the MP for Newcastle-under-Lyme, Aaron Bell, and former policy chief Munira Mirza, were “disappointing” but insisted “it’s not many”. “The vast majority of Conservative MPs are right behind the prime minister because he has delivered, he has consistently delivered, and he will continue to do so,” she told BBC Radio 4’s Today programme. Gibb, the MP for Bognor Regis and Littlehampton, wrote in the Daily Telegraph: “I am sorry to say that it is hard to see how it can be the case that the prime minister told the truth.” He has also reportedly submitted a letter of no confidence to the chairman of the 1922 Committee. In response, Dorries insisted that “the prime minister has told the truth.” She suggested remainers are plotting against the prime minister. She said: “There are a small number of voices, whether they are people who were ardent supporters of remain, who see this as their last opportunity to reverse Brexit.” But the Conservative MP Stephen Hammond said that was “predictable rubbish from a predictable source”. He told the BBC’s Week in Westminster: “I think, as far as I can see, the people who so far declared that they’ve written a letter are from all wings of the party and none.” Asked whether Johnson needs to change, Dorries launched an impassioned defence of the prime minister, saying: “I’d be cautious of asking the prime minister who’s delivered us the largest majority since Margaret Thatcher to change.” She added: “That commitment to delivery, both on vaccines and on employment and on many issues, I want the prime minister, that prime minister, who has that kind of onwards mentality, I want that to remain. I don’t want that to change.” Responding to Rishi Sunak’s response on Thursday distancing himself from the prime minister’s false claim that the Labour leader, Keir Starmer, failed to prosecute paedophile Jimmy Savile, Dorries said the chancellor was “entitled to his views” but defended Johnson’s response. “What I would say is that when you lead an organisation, you are responsible,” she said. Speaking on Sky News, Dorries insisted that 97% of Tory MPs back the prime minister and that Sajid Javid, the health secretary, is fully behind him, despite distancing himself from Johnson’s Savile claim. She said Javid was “quite shocked” about how his comments had been reported and that he was “100% behind the prime minister”. During another media appearance, on BBC Breakfast, Dorries said the prime minister was “very positive” when she communicated with him in the past 24 hours, but questioned why she was being asked whether she had spoken to him. Meanwhile, former minister Liam Fox said he has not submitted a letter of no confidence and that “it’s very clear” that the Conservatives’ 15% threshold for a no-confidence vote had not been reached. But the MP for North Somerset said he was “waiting to see what comes out of” the full Gray report. The partygate debate, he said, was “diminishing the focus” from other political issues such as inflation rises and Ukraine and damaging perceptions of UK politics both at home and abroad. He said: “The whole issue round whether rules were broken in Downing Street in 2020 now needs to be resolved by what the police are investigating. We didn’t get the full coverage of what Sue Gray had said and I think we need to get all this information.”