Boris Johnson has insisted the UK needs to move on from partygate after the Sue Gray report revealed a slew of lockdown-breaching events at Downing Street.
The prime minister said he took "full responsibility" for the scandal but defied renewed calls to resign as he sought to play down his personal involvement in the gatherings.
He said he "overwhelmingly" believes he should remain in office despite public anger at the "bitter and painful" conclusions of the inquiry.
Mr Johnson apologised for attending his own birthday party during the first lockdown, for which he was fined by the police, but said he was not fined for any other events.
The full report, delayed for four months by a separate Met Police investigation, gave a damning insight - with photos - into 16 parties in Downing Street and Whitehall that took place while COVID restrictions were in place in 2020 and 2021.
• A large number of people attended events and breached COVID guidelines
• Staff felt unable to raise concerns about behaviour
• Excessive alcohol consumption was reported, one person was sick and there was a fight
• Drunkenness was reported and staff were told to leave via the back door
• One event went on until 4.20am
• Senior leadership - political and official - must bear responsibility for the culture
• Those in most junior positions attended gatherings at which their seniors were present, or had organised
• There were "multiple examples" of a lack of respect and poor treatment of security and cleaning staff.
In one message after a "bring your own booze" party to which 200 people were invited in May 2020, Martin Reynolds, the prime minister's principal private secretary, said: "We seem to have got away with [it]."
It was revealed that Ms Gray abandoned her investigation into an "Abba party" in Mr Johnson's flat celebrating the departure of Dominic Cummings, the prime minister's chief adviser, in November 2020 because she had only collected "limited" information when the Met began its investigation.
She established Mr Johnson was there and that alcohol and food were on offer.
PM defiant in apology
Mr Johnson said much of the report was "news to me" as he said he was unaware of many of the events that went on after his own brief appearances. He said he was "appalled" when he learned of them.
He told a Downing Street news conference: "I understand why people are indignant and why people have been angry at what took place."
Pressed by Beth Rigby, Sky News's political editor, on whether he ever considered resigning, he said: "I overwhelmingly feel it is my job to get on and deliver.
"No matter how bitter and painful that the conclusions of this may be - and they are - and no matter how humbling they are, I have got to keep moving forward and the government has got to keep moving. And we are."
The prime minister also denied lying to the Commons when he previously told MPs that all rules had been followed, insisting he truly believed that at the time.
As Mr Johnson tries to move on from partygate, the Treasury confirmed the chancellor will announce further cost of living plans on Thursday - brought forward from early June.
Growing Tory anger
Cabinet ministers, including Foreign Secretary Liz Truss and Justice Secretary Dominic Raab, lined up to offer the prime minister their backing.
But long-time critic and Conservative MP Tobias Ellwood asked the PM: "Can he think of any other prime minister who'd have allowed such a culture of indiscipline to take place under their watch and if it did would they not have resigned?"
Conservative MP Julian Sturdy later tweeted he feels the Gray report has shown "it is now in the public interest for the prime minister to resign".
Labour calls for PM to resign
Labour leader Sir Keir Starmer said the report "will stand as a monument to the hubris and arrogance of the government that believes it was one rule for them and another for everyone else".
He told Mr Johnson it was "time to pack his bags" and the Tories had "set the bar for his conduct lower than a snake's belly".
The prime minister in turn called Sir Keir "Sir Beer Korma" in reference to an investigation he is facing over an alleged lockdown-breaking event in Durham.
Mr Johnson also denied he had asked Ms Gray if she needed to publish her report after the Met Police concluded its investigation last week.
Lib Dem leader Sir Ed Davey said: "Any other PM would be forced to resign by a report as damaging as this, yet still Conservative MPs defend Johnson and allow him to cling on."