Prime Minister Boris Johnson on Tuesday apologised to MPs after he became the first UK leader fined for breaking the law, but faced opposition calls to quit for the sake of integrity in politics.
Addressing parliament for the first time , he reiterated that he did not think he had done anything wrong when he attended an office gathering for his birthday in June 2020, when Britain was under a pandemic lockdown.
"That was my mistake and I apologise for it unreservedly," he said.
The British public "had a right to expect better of their prime minister", Mr Johnson added, while insisting he would get on with the job including to defend Ukraine against Russia's "barbaric" invasion.
The conflation of issues led to charges that Mr Johnson was seeking to bury — which have also embroiled his finance minister and wife.
Mr Johnson could yet receive further fines over various Downing Street parties held despite strict coronavirus lockdowns imposed by his own government over the past two years.
MPs will hold a special debate on Thursday into whether he misled the House of Commons when, in December, he denied ever breaking the rules. He will be on an official visit to India by then.
Knowingly misleading parliament is a breach of government ministers' code of conduct, which states they should resign as a result — and opposition lawmakers are adamant he should go.
But asked directly if he deliberately misled parliament, Mr Johnson emphatically replied: "No."
Opposition Labour leader Keir Starmer said there was cross-party support towards Britain's backing for Ukraine, and any Conservative successor would continue Mr Johnson's war policy.
Mr Starmer recounted the experience of one member of the public who, because of the COVID-19 rules then in place, was denied the chance to hold his dying wife's hand in hospital.
Mr Johnson was "a man without shame" backed by "nodding dogs" in his cabinet, Mr Starmer said, urging Conservative MPs to eject their leader.
They should "bring decency, honesty and integrity back into our politics and stop the denigration of this country", the Labour leader said.
'Fury has not receded'
One national survey suggested around two-thirds of the public spoke negatively about Mr Johnson, compared to just 16 per cent positively, with the word "liar" the most commonly shared response.
"Overall, 'partygate' dominates views of Boris over Ukraine," said James Johnson, a Conservative pollster who conducted the sample.
"Fury has not receded. Many negative comments are by people who liked him previously but have now changed their minds."
Voters will get their chance to deliver a verdict on 5 May, when the UK holds nationwide elections for local and city councils.
A demonstrator poses for a photograph holding a placard calling for the resignation Boris Johnson, as they protest outside the entrance to 10 Downing Street, the official residence of the UK prime minister, in central London on 13 April, 2022. Source: AAP / TOLGA AKMEN/AFP via Getty Images
David Wolfson, a justice minister, has already resigned from the government, citing "the scale, context and nature" of the rule breaches.
Mr Johnson will bid to shore up his standing with backbenchers when he addresses a meeting of the Conservative parliamentary party on Tuesday evening.
But one senior Tory backbencher, Mark Harper, responded to Mr Johnson in the Commons that he was "no longer... worthy" of being prime minister after his apology.
London's Metropolitan Police is investigating dozens of alleged lockdown breaches by Mr Johnson and his staff in the Downing Street complex where he lives and works.
It said last week officers had so far issued more than 50 fines.
The scandal, the latest in a stream of controversies to hit Mr Johnson since last year, left his position hanging by a thread and MPs from his Conservative Party in a rebellious mood.
But he boosted his survival chances with what is seen as a firm response to Ukraine, which diverted attention away from the furore when he was most vulnerable in February.
Britain's cost-of-living crisis is also credited with distracting people from the scandal, while Mr Johnson has made several big policy announcements aimed at his pro-Brexit political base.
They include controversial plans to send migrants and asylum seekers who cross the Channel to Rwanda.