London CNN  — 

British Prime Minister Boris Johnson was dealt a huge and sudden blow on Tuesday when two of his top ministers announced their resignations, saying they could no longer work for a government mired in scandal.

Chancellor Rishi Sunak and Health Secretary Sajid Javid announced their decisions to quit within minutes of each other on Tuesday evening, plunging Johnson’s troubled administration into renewed chaos and prompting a wave of other junior ministers and officials to resign.

Some called on Johnson himself to step down, and there was speculation that if he refused to go, members of his own party would launch a formal effort to unseat him – less than a month after the last one failed.

The immediate cause of the resignations was the bungled handling of a recent controversy, but came against the backdrop of months of turmoil in which Johnson was fined by police for breaking Covid-19 lockdown rules.

“The public rightly expect government to be conducted properly, competently and seriously,” Sunak said in his resignation letter, posted to Twitter. “I recognise this may be my last ministerial job, but I believe these standards are worth fighting for and that is why I am resigning.”

“I am sad to be leaving Government but I have reluctantly come to the conclusion that we cannot continue like this,” Sunak added.

Javid wrote that “it has been an enormous privilege to serve in this role, but I regret that I can no longer continue in good conscience.” Javid added that the vote of confidence in the prime minister last month “was a moment for humility, grip and new direction.”

“I regret to say, however, that it is clear to me that this situation will not change under your leadership – and you have therefore lost my confidence too,” Javid wrote.

Other ministers and officials occupying more junior posts in the government quit in the hours that followed, with more resignations continuing on Wednesday morning. Johnson moved to shore up his position, replacing his two Cabinet ministers late on Tuesday.

Scandal after scandal

The latest crisis blew up out of Downing Street’s handling of last week’s resignation of deputy chief whip Chris Pincher, who stepped down from his post last Thursday amid allegations he had groped two guests at a private dinner the night before.

While he did not admit the allegations directly, Pincher said in a letter to Johnson that “last night I drank far too much