LONDON -- Prime Minister Boris Johnson apologized Monday after an inquiry found that Downing Street parties while Britain was in lockdown represented a 鈥渟erious failure鈥 to observe the standards expected of government or to heed the sacrifices made by millions of people during the pandemic

Johnson brushed off calls to quit over the 鈥減artygate鈥 scandal, promising to reform the way his office is run and insisting that he and his government can be trusted. But he faced criticism from some of his own Conservative colleagues, who have the power to oust a leader some fear has become damaged goods. One Conservative lawmaker accused the prime minister of taking him for 鈥渁 fool.鈥

鈥淚 get it, and I will fix it,鈥 he said in Parliament after senior civil servant on several gatherings in 2020 and 2021 while the U.K. was under government-imposed restrictions to curb the spread of the coronavirus.

Gray found that 鈥渇ailures of leadership and judgment鈥 allowed events to occur that 鈥渟hould not have been allowed to take place.鈥

鈥淭he hardship under which citizens across the country worked, lived and sadly even died while observing the government's regulations and guidance rigorously are known only too well,鈥 Gray wrote.

鈥淎gainst the backdrop of the pandemic, when the government was asking citizens to accept far-reaching restrictions on their lives, some of the behavior surrounding these gatherings is difficult to justify,鈥 she added.

Gray's glimpse inside a 10 Downing St. marked by excessive alcohol consumption and staff afraid to speak out about workplace problems are a blow to Johnson, despite the fact that Gray's conclusions relate to just four of the 16 events she investigated.

Her findings on 12 others have been withheld at the request of the Metropolitan Police force, to avoid 鈥渁ny prejudice鈥 to a criminal investigation launched last week into the most serious alleged breaches of coronavirus rules.

The force said Monday that it would be interviewing party attendees and looking at more than 300 photos and over 500 pages of documents it had received from Gray's team. Anyone found guilty, including the prime minister, could face a fine.

Among the events under police investigation are a June 2020 birthday party for Johnson in Downing Street and two gatherings held on the eve of Prince Philip's funeral in April 2021 - a service at which the widowed Queen Elizabeth II had to sit alone.

The allegations that the prime minister and his staff flouted restrictions imposed on the country - holding 鈥渂ring your own booze鈥 office parties, birthday celebrations and 鈥渨ine time Fridays鈥 - have caused public anger, led some Conservative lawmakers to call for Johnson's resignation and triggered intense infighting inside the governing party.

Opposition Labour Party leader Keir Starmer said the British public had made 鈥渉eart-wrenching sacrifices鈥 and endured 鈥渁 collective trauma鈥 during the pandemic.

He said the prime minister 鈥渉eld people's sacrifice in contempt. He showed himself unfit for office.鈥

Johnson can ignore opposition criticism, because the Conservatives have a large majority in Parliament. His fate rests on how Conservative lawmakers respond to his apology. Some previously said they would push for a no-confidence vote if Gray found Johnson was at serious fault or had misled Parliament with his previous insistence that no rules had been broken. If Johnson lost such a vote, he would be replaced as party leader and prime minister.

Johnson urged his critics to wait for the conclusions of the police investigation.

But one Conservative legislator, Andrew Mitchell, said in the House of Commons that Johnson 鈥渘o longer has my support.鈥

Another, Aaron Bell, recalled attending his grandmother's small, socially distanced funeral in May 2020 and asked: 鈥淒oes the prime minister think I'm a fool?鈥

Former Conservative Prime Minister Theresa May said that either Johnson and those around him 鈥渉ad not read the rules, or didn't understand what they meant. â鈧¦ Or they didn't think the rules applied to them. Which was it?鈥

Gray did not criticize the prime minister directly, but said 鈥渢here is significant learning to be drawn from these events which must be addressed immediately across government.鈥

That is unlikely to satisfy many of Johnson's critics, some of whom accused the government of an attempted cover-up.

鈥淭his whole thing is a whitewash, there is no intent for anyone to tell the truth or be held accountable,鈥 said David Garfinkel, a member of the group COVID-19 Bereaved Families for Justice. 鈥淲e have a prime minister who lies, who lies about lies and he is utterly insincere and incapable of leading.鈥

The government initially refused to promise that it would publish Gray's full findings once the police investigation is finished. But after pressure from Conservative lawmakers, Johnson's office committed to publishing her updated report.

Johnson, meanwhile, sought to change the subject from his personal woes, marking the second anniversary of Brexit on Monday by touting economic opportunities outside the European Union.

The U.K. officially left the now 27-nation bloc on Jan. 31, 2020, though it remained part of the EU's economic structures for another 11 months.

Johnson announced a 鈥淏rexit Freedoms鈥 Bill that the government says will slash red tape for British businesses by amending laws that were carried over from the U.K.'s years as an EU member.

Johnson also plans a diplomatic push to try to ease tensions between Russia and Ukraine. He is expected to speak to Russian President Vladimir Putin by phone later Monday or Tuesday and to visit Ukraine on Tuesday as part of efforts to deter Russia from invading its neighbor.

Some political observers said Gray's circumscribed and partial report may give Johnson at least a temporary reprieve from calls for his ouster.

鈥淚t's too soon to tell,鈥 said Alex Thomas, program director at the Institute for Government think-tank.

鈥淚t avoided some of the most damaging outcomes that we might have expected. ... But in a way the more you read it, the more you look at the descriptions of the culture and the failings of leadership, the more damaging it was.鈥

Associated Press writer Sylvia Hui and video journalist Jo Kearney contributed to this story.