LONDON: Boris Johnson's former communications chief apologized "unreservedly" on Friday for a lockdown-breaching party in Downing Street last year, the latest in a string of rule-breaking social events that are threatening to topple the British prime minister.
James Slack said his April 2021 job-leaving party "should not have happened at the time that it did."
"I wish to apologise unreservedly for the anger and hurt caused," Slack said in a statement.
"I am deeply sorry, and take full responsibility," added Slack, who left the government last year and is now deputy editor-in-chief of tabloid newspaper The Sun.
Johnson is not alleged to have attended the leaving party, disclosed by the Daily Telegraph newspaper.
Earlier this week he apologized for going to another gathering in the garden of Downing Street, his office and home, in May 2020, when the U.K. was under strict lockdown.
The latest party has appalled many in Britain because of the symbolism of its timing, April 16, 2021, the night before the funeral of Queen Elizabeth II's husband, Prince Philip.
The Daily Telegraph said Downing Street staff drank, danced and socialized at leaving parties for Slack and another staff member on April 16 last year.
The next day, the widowed queen sat alone in the church during her husband's funeral service in order to adhere to social distancing rules that barred indoor mixing.
Photos of the monarch, clad in black and wearing a face mask, became a powerful image of the isolation and sacrifice endured by many during the pandemic.
Members of Johnson's Conservative government have expressed support for Johnson following his admission on Wednesday that he attended a bring your own booze staff party in the garden of his Downing Street office in May 2020.
At the time people in Britain 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.
The latest revelations are likely to prompt more Conservatives to join opponents and demanding that Johnson resign for flouting the rules the government imposed on the country as the coronavirus swept the U.K.
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.
On Wednesday 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 respected public servant who has investigated past allegations of ministerial wrongdoing, is expected to report by the end of the month.
The government says Gray's inquiry is independent, but she is a civil servant and Johnson is, ultimately, her boss.
Gray could conclude that Johnson broke the code of conduct for government ministers, though she does not have the power to fire him.
Johnson has not said what he will do if she found he was at fault.
Johnson does not have to face voters' judgment until the next general election, scheduled for 2024.
But his party could seek to oust him sooner if it judges he has become toxic.
Under Conservative rules, a no-confidence vote in the leader can be triggered if 15% of party lawmakers write letters demanding it.
Roger Gale, a Conservative lawmaker who has long been critical of Johnson, said he had already submitted a letter calling for a leadership challenge.
"I do think that minds are now, over this weekend, being focused upon the need to take the necessary action," he said.
"I clearly don't know, and I shouldn't know, how many of my colleagues have put in letters, but I believe that there is some momentum which is growing."
Johnson on Friday faces mounting leadership pressure amid further allegations of parties held at his 10 Downing Street office-residence by staff, which were categorised as a 'partygate' scandal due to the apparent serial breaches of lockdown rules in place at that time.
The Daily Telegraph newspaper has reported on two farewell parties comprising around 30 people drinking alcohol and dancing to music until the early hours of April 17 last year, the night before the funeral of Prince Philip, the Duke of Edinburgh.
Restrictions at the time banned indoor gathering between different households and Queen Elizabeth II sat alone during the funeral ceremony for her late husband, in keeping with the social distancing rules.
"This event should not have happened at the time that it did. I am deeply sorry, and take full responsibility," said James Slack, the UK Prime Minister's former Director of Communications, who was at the centre of the farewell party that led to the party last April.
Slack, now the deputy editor-in-chief at 'The Sun' newspaper, apologised "unreservedly for the anger and hurt caused".
While Johnson was not present at either of the two gatherings in April 2021, since he was spending the weekend at his Buckinghamshire country estate Chequers, the latest revelations add to the saga around rules being broken at the heart of the UK government.
Ministers have insisted that top civil servant Sue Gray's ongoing internal investigation into such gatherings will determine the extent of wrongdoings and therefore judgement should be reserved until her probe concludes.
"If the details that are in this story turn out to be true, clearly people are going to form their judgement," UK Security Minister Damian Hinds said on Thursday, with reference to the fresh revelations which call Johnson's leadership of his party and country into question.
"I am entirely behind the Prime Minister and the government, and I think the leadership that the Prime Minister has shown, particularly through the coronavirus, has been very strong," Hinds said.
But battle lines have been drawn within the Conservative Party, with many of Johnson's own MPs demanding he step down.
"I want to apologise. I know that millions of people have made extraordinary sacrifices in the last 18 months. I know the rage they feel with me and with the government I lead when they think that in No.10, rules are not being followed," Johnson said in the House of Commons earlier this week with reference to a garden party in May 2020 that he had attended.
He said that he "believed implicitly" that it was a work-related event but regretted not breaking up the gathering and "sending everyone back inside".
Johnson's hopes now hang on the ongoing internal investigation exonerating him of wrongdoing, with talk around potential successors gaining ground.
UK Chancellor Rishi Sunak is seen as a frontrunner to take over as Prime Minister, with the Indian-origin cabinet minister agreeing that his boss was "right to apologise".
Betfair, a major bookmaker in the UK on Thursday slashed its odds that the embattled 57-year-old will resign soon, with Sunak, who is the Chancellor of the Exchequer since February 2020, odds on favourite to step in at the 10 Downing Street.
Meanwhile, the Opposition is keeping up the pressure on Johnson, with Liberal Democrat Leader Ed Davey demanding his immediate resignation.
"The Queen sitting alone, mourning the loss of her husband, was the defining image of lockdown. Not because she is the Queen, but because she was just another person, mourning alone like too many others. Whilst she mourned, Number 10 partied. Johnson must go," Davey said.
"I have no words for the culture & behaviours at number 10 and the buck stops with the PM," the Labour Party's Deputy Leader Angela Rayner tweeted.