(Bloomberg) --

Boris Johnson suffered a major setback as he seeks to hold onto power after a member of Parliament in his ruling U.K. Conservative Party defected to the main opposition.

The move by Christian Wakeford, who was elected in 2019 in one of the many so-called red wall seats that swung from Labour to Johnson’s Tories in the general election, was confirmed by opposition leader Keir Starmer.

Johnson’s weakening position was further highlighted by a new poll showing support for the Conservatives has plummeted in red wall seats across England’s north and Midlands. Labour now has an 11-point lead in the areas it traditionally held but which flipped to Johnson’s Tories in 2019, according to a JL Partners poll for Channel 4 News.

A group of the Tory party’s 2019 intake gathered Tuesday to discuss whether they should try and bring Johnson down, with the threat of a leadership contest moving ever closer. Many MPs are furious at Johnson’s handling of claims that he and his staff held parties in Downing Street during the pandemic, a time when such gatherings were banned.

Pressed in Prime Minister’s Questions on whether it was time to resign, Johnson replied: “No.” He said he apologized “sincerely” for “any misjudgments that were made” over alleged gatherings, and it was right to wait for the conclusion of an inquiry by senior civil servant Sue Gray.

A no-confidence vote would be triggered if 54 Tory MPs send letters to a key committee calling for Johnson to resign -- but the number of letters submitted is a closely guarded secret. Several MPs have publicly said they have sent letters already, but many are expected to have done so privately.

In an attempt to win back party support, Johnson is widely expected to announce later on Wednesday that Covid-19 restrictions in England will soon be eased -- a move that has long been called for by many Conservative MPs concerned at the impact on people’s freedoms.

Tensions have been brought to breaking point after Johnson’s former top aide Dominic Cummings accused the prime minister of lying to Parliament, saying he would “swear under oath” that the premier both was aware of and allowed a drinks party at Downing Street in May 2020.

©2022 Bloomberg L.P.