The Tory MP Christian Wakeford has defected to Labour, piling more pressure on Boris Johnson as growing numbers within his own party call on the prime minister to resign. Just minutes before prime minister’s questions, Wakeford – elected as the MP for Bury South in 2019 – crossed the floor to sit with Keir Starmer’s party, declaring in a letter to Johnson resigning the Conservative whip that he was “incapable of offering the leadership and government this country deserves”. The move will prove a huge embarrassment for Johnson, who is fighting to avoid enough of his own backbenchers submitting letters calling for a no-confidence vote. Fifty-four are needed to trigger a ballot. Many of those who have written a letter are members of the 2019 intake, like Wakeford. He submitted a letter last week. In a letter to Johnson released on Wednesday afternoon, Wakeford said he believed “the policies of the Conservative government that you lead are doing nothing to help the people of my constituency and indeed are only making the struggles they face on a daily basis worse”. Raising concerns about the “cost of living crisis” and how the country should emerge from the Covid pandemic, Wakeford said the UK needed “a government that upholds the highest standards of integrity and probity in public life”. He added: “Sadly, both you and the Conservative party as a whole have shown themselves incapable of offering the leadership and government this country deserves.” Wakeford said he was in “no doubt” his constituents would be best served “by my joining a party that genuinely has their interests at heart”, and admitted he had “wrestled with my conscience for many months”. But he said the decision was “about much more than your leadership and the disgraceful way you have conducted yourself in recent weeks” during the investigation into alleged rule-breaking parties held in Downing Street and across government. Wakeford said Starmer had “shown that integrity in the way he has led his party on issues that matter to me, not least the vital challenge of combatting antisemitism” and added: “Changes that can only be delivered by a Labour government with Keir Starmer.” To raucous cheers in the Commons chamber, Starmer “warmly welcomed” Wakeford to the opposition benches – gesturing to the MP who was sat directly behind him. “Like so many people up and down the country, he has concluded that the prime minister and the Conservative party have shown themselves incapable of offering the leadership and government this country deserved.” Johnson attempted to appear bullish in front of his own MPs, telling them: “The Conservative party won Bury South for the first time in generations under this prime minister, with an agenda of uniting and levelling up and delivering for the people of BS, and we will win again in BS at the next election under this prime minister.”