Boris Johnson is in even more jeopardy as a result of the Partygate affair, with a source claiming that a fine was imposed for a second event attended by the prime minister, and top Conservatives warning that he might face a leadership challenge within weeks.

No. 10 was compelled to deny on Friday evening that Johnson had received another fixed penalty notice (FPN) for a "bring your booze" Downing Street garden party on May 20, 2020.

In January, Johnson admitted to attending the event for roughly 25 minutes during the first national lockdown, when indoor and outdoor social mixing was prohibited, but stated he "believed implicitly that this was a professional function." Martin Reynolds, Johnson's chief private secretary, is alleged to have invited up to 100 people to the "socially separated" evening cocktails.

According to the Guardian, at least one FPN was issued to a Downing Street staffer who attended the event on Friday. A spokeswoman for Johnson said he had not received a new fine as he returned from a two-day trade trip to India on Friday.

The Metropolitan Police announced on Thursday that it would not provide any updates on FPNs for Downing Street lockdown breaches until after next month's local elections "due to the restrictions around communicating" ahead of the 5 May vote, though criminal investigations and fines could still be issued.

Johnson's leadership challenge

This comes as senior party figures cautioned that if the Conservatives suffer big losses in the May elections, Boris Johnson will almost certainly face a leadership challenge.

The prime minister's support was "markedly reduced" as the government caved down and agreed to allow a third probe alleged lockdown violations, igniting new bidding wars among those trying to succeed him.

MPs said allies of Jeremy Hunt, the former health secretary, and Penny Mordaunt, the trade minister, had renewed covert plans for a leadership election.

Moreover, conservative peer and elections expert Robert Hayward said MPs, councilors, and Tory groups were concerned that the Partygate saga might drag on indefinitely. "I expect that there will be some sort of leadership struggle at some point, but not soon," he told the BBC. "However, support for the Prime Minister has been steadily eroding during the recess."

Given the many probes by Scotland Yard, senior civil servant Sue Gray, and now the Commons privileges committee, Hayward predicted Johnson's demise would be "death by a thousand cuts."

He stated that MPs were "searching about" for the best alternative for Johnson, adding, "They won't necessarily accept it, but that is the fact."

How will the elections turn out? 

A cabinet source reportedly predicted that the May 5 local elections will be as bad for the Conservatives as the 2019 European Parliament elections, in which the party received its lowest-ever share of the vote.

Former Tory party leader Iain Duncan Smith said many MPs had not become more hostile to Johnson as a result of the bad handling of the vote concerning the prime minister being investigated for deceiving parliament.

However, he told the Guardian: “We’ll wait to see what happens at the end of this. The majority of the public is sick and tired of the story; Conservative MPs are sick and tired of the story.

“Colleagues may decide it is recoverable. If they reach the decision it’s too damaging, then it’s over. That balance is just sitting waiting. I fancy that the local elections and inquiry will put that to rest.”

Former health minister Steve Brine was also found to have advised a constituent that a vote of confidence in Johnson "should take place... sooner rather than later."

"This is not a sustainable condition," he wrote in an email, "and I believe additional FPNs will follow those given last week. I'll be working with top colleagues to ensure that confidence is put to the test in the coming months."