LONDON (AP) - With varying degrees of enthusiasm, senior British government ministers on Thursday expressed support for Conservative Prime Minister Boris Johnson and rejected demands he resign for attending a garden party during the country's first coronavirus lockdown.

Many other Conservatives held their tongues, waiting to see whether the crisis threatening Johnson's premiership will fade or intensify.

Pressure on the beleaguered leader looked set to build after a newspaper published allegations of two more parties by staff in the prime minister's office, complete with drinking, music and dancing. The Daily Telegraph said the leaving parties for two staffers took place in April 2021, the night before the funeral of 99-year-old Prince Philip, the husband of Queen Elizabeth II. The queen sat alone in the church during the service in order to adhere to social distancing rules that barred indoor mixing.

The new revelation came a day after Johnson apologized in the House of Commons for attending a “bring your own booze” party in the garden of the prime minister's Downing Street office and residence in May 2020. About 100 staff were invited by a senior prime ministerial aide to what was billed as a “socially distanced drinks” event.

At the time Britons were banned by law from meeting more than one person outside their households as part of measures to curb the spread of the coronavirus. Millions were cut off from family and friends, and even barred from visiting dying relatives in hospitals.

Johnson said he understood public “rage,” but stopped short of admitting wrongdoing, saying he had considered the gathering a work event to thank staff for their efforts during the pandemic.

Johnson urged people to await the conclusions of an investigation by senior civil servant Sue Gray into multiple alleged rule-breaking parties by government staff during the pandemic. Gray, a public service veteran with a reputation as a straight-shooter, is expected to report by the end of the month.

Johnson spent Thursday holed up in Downing Street as waves of support, anger and disbelief about his version of events swept through Britain's political system, and the country. A planned visit to a coronavirus vaccination center was called off after a family member tested positive for the coronavirus, the prime minister's office said.

Northern Ireland Secretary Brandon Lewis said Johnson's apology had been “very, very sincere” - but added that the prime minister did not believe he had done anything wrong.

“The prime minister has outlined that he doesn't believe that he has done anything outside the rules,” Lewis told Sky News. “If you look at what the investigation finds, people will be able to take their own view of that at the time.”

Gray does not have the power to punish politicians, and Johnson did not say what he would do if she found he was at fault.

Foreign Secretary Liz Truss - often cited as a possible successor to Johnson - tweeted: “I stand behind the Prime Minister 100% as he takes our country forward.”

Treasury chief Rishi Sunak, another potential rival for the top job, was more muted. He tweeted that “The PM was right to apologise and I support his request for patience while Sue Gray carries out her enquiry.” Sunak was notably absent from the House of Commons during Johnson's statement on Wednesday; he was 200 miles (320 kilometers) away on a visit to southwest England.

Opposition politicians say Johnson should resign for attending the party and for his previous denials that any rule-breaking took place.

Many Conservatives fear the “partygate” scandal could become a tipping point for a leader who has weathered a series of other storms over his expenses, and his moral judgment.

Some have joined opposition calls for Johnson to quit. Douglas Ross, the leader of Conservatives in Scotland, said Johnson's position “is no longer tenable.” Lawmaker Roger Gale called the prime minister a “dead man walking,” and colleague Caroline Nokes said Johnson “looks like a liability.”

Johnson has shown no sign that he plans to resign. His spokesman, Max Blain, said the prime minister was not sitting around musing on his strengths and weaknesses.

“I don't think self-reflection is his priority,” Blain said. “His priority is on delivering for the public.”

If he does not resign, Johnson could be ousted by a no-confidence vote among party legislators, which would be triggered if 15% of Conservative lawmakers write letters demanding it. It's unclear how many letters have already been submitted.

Senior Labour Party legislator Lisa Nandy said the police, and not just a civil servant, should be investigating the alleged multiple rule-breaches. The Metropolitan Police Force said it was waiting to see whether Gray's inquiry uncovered “evidence of behavior that is potentially a criminal offense.”

Nandy said there was “immense” public anger over the party revelations.

“Based on what I'm seeing pouring into my inbox this morning, I think the prime minister should not be confident that he'll survive this,” she said.

Many Conservatives were waiting to see how reaction to the crisis develops in the coming days.

Conservative lawmaker Philip Dunne said the allegations were “very serious.”

“I think the prime minister was quite right to apologize yesterday, and I think it is right that we wait to see what the investigation from Sue Gray establishes,” he told Times Radio. “People will then have to suffer the consequences of whatever happens.”