Labour have urged Rishi Sunak to “come clean” over what he knew about Partygate rule-breaking.
It comes as the Prime Minister faced further questions over his Commons denials over lockdown-busting gatherings.
MPs are set to vote on Monday on Boris Johnson ’s punishment for misleading the House of Commons over the parties.
Despite Mr Johnson having resigned as an MP, the vote will approve the Privileges Committee’s recommendation of a 90-day suspension, and the ex-PM being banned from holding a Parliamentary pass.
MPs are usually entitled to come and go from Parliament as they please using a lifetime pass. Only on a few occasions have MPs been banned from receiving such a pass.
Meanwhile, Mr Sunak is under scrutiny over an answer he gave in the Commons on December 7, 2021 - while he was Chancellor.
In answer to a question from Labour MP Karl Turner about whether he attended Downing Street Christmas parties, Mr Sunak replied: “No, I did not attend any parties.”
Four months later, in April 2022, Mr Sunak paid a fixed penalty notice fine for attending Mr Johnson’s Downing Street birthday party.
Now Labour chair Anneliese Dodds has written to Mr Sunak to demand “honesty” over the “culture of brazen rule-breaking” in No10 during the Covid lockdowns.
“You yourself lived in the house where this unacceptable behaviour was taking place,” she wrote.
“You were working closely with the Prime Minister throughout this period. And you yourself received a fine for one of the gatherings. No10 was described by one whistleblower as an "island oasis of normality" where covid rules didn't apply, but where staff were told to be mindful of cameras outside.”
She told the Sunday Mirror: “Boris Johnson was never fit to be Prime Minister, that much is obvious. Tasked with seeing the country through a pandemic, he broke the rules and lied to cover his tracks.
“But the parties were happening in the very house where Rishi Sunak lived. He knew that Johnson was a rulebreaker and a liar and he propped him up every step of the way.
“ Rishi Sunak might think he leads a government of professionalism, integrity and accountability, but the British people can see it for what it is: a party led by a weak Prime Minister, drowning in sleaze, incapable of getting a grip on the crises in our economy, mortgage markets or NHS.
“The country needs a general election and a Labour government.”
A bombshell video exposes for the first time how officials joked about their lockdown rule-bending Christmas bash at the Conservative Campaign Headquarters in London, the Mirror revealed.
In the exclusive footage, two dancers even twirl past a sign saying “Please keep your distance”.
