Scandal, Rebellion, Election Loss and a Resignation: Was This Boris Johnson's Worst Week Ever?

The resignation of a senior member of U.K. Prime Minister Boris Johnson's Cabinet capped a week that saw his Conservative Party endure a stunning election defeat amid weeks of scandal over pandemic rule-breaking Christmas parties and soaring COVID-19 cases.

In his resignation letter as Brexit Minister, Lord Frost said he hoped Johnson would not be "tempted" by "coercive measures" to tackle COVID-19.

Frost's decision was sparked by the introduction of new pandemic restrictions, which include a requirement that people show proof of vaccination or a negative coronavirus test to enter nightclubs and other crowded venues, according to The Mail on Sunday newspaper, which first reported his resignation.

It came after Johnson faced the biggest rebellion of his tenure as prime minister when almost 100 Conservative lawmakers voted against his proposal for the measures. Scientific advisers have warned that more far-reaching restrictions are needed to stop hospitals from being overwhelmed.

Britain's Prime Minster Boris Johnson
Britain's Prime Minster Boris Johnson speaks with members of the Metropolitan Police in their break room, as he makes a constituency visit to Uxbridge police station on December 17, 2021 in Uxbridge, England. Leon Neal/Getty Images

It comes as the U.K. continues to see record COVID cases, with more than 90,000 confirmed on Saturday alone. At least 10,000 were confirmed to be Omicron infections.

Frost's resignation also comes after a major defeat for Johnson's Conservative Party in a parliamentary by-election in North Shropshire, once a safe seat for the Conservatives.

The loss to the Liberal Democrats was seen as a referendum on Johnson's government, which has also come under fire over reports that officials held Christmas parties last year when rules forbid such gatherings.

The scandal erupted after a video surfaced that showed some of Johnson's staff appear to joke about a party that violated the rules at a mock news conference. Before that, Johnson repeatedly denied government officials had broken any lockdown rules.

On Saturday, Cabinet Secretary Simon Case, who was chosen by Johnson to investigate the claims, was forced to step aside after it emerged that an event was held in his own office when rules forbidding them were in place.

The Guido Fawkes website first reported Friday that Case's office held two parties in December 2020.

Johnson is also facing claims that he joined staff at a party in Downing Street during the U.K.'s first national lockdown.

The prime minister spent about 15 minutes at the alleged gathering on May 15 last year, where sources said about 20 staff drank wine and spirits and ate pizza, the Guardian and Independent reported. Johnson reportedly told one aide that they deserved a drink for "beating back" coronavirus.

Johnson's reputation has also been tarnished in recent months by a scandal over the expensive refurbishment of the Downing Street apartment and a lobbying row, fueling speculation that he could soon face a leadership challenge.

"A Government in total chaos right when the country faces an uncertain few weeks," Angela Rayner, the deputy leader of the opposition Labour Party, tweeted on Saturday.

"@BorisJohnson isn't up tot he job. We deserve better than this buffoonery.″

Downing Street has been contacted for comment.