Sue Gray has blamed a "failure of leadership" for allowing parties to take place in Downing Street when the country was under strict lockdown.

In long-awaited findings, the senior civil servant says some events "should not have been allowed to take place".

Ms Gray investigated 16 separate gatherings - including three that were not previously known about.

Boris Johnson said he accepted the findings in full, as he faced questions and criticism from MPs.

In Ms Gray's findings, she confirms that the Metropolitan Police is investigating 12 events - on eight separate dates - for alleged Covid-rule breaking.

These include the 20 May 2020 "bring your own booze" event in the Downing Street garden, which the PM has apologised for attending, and the PM's birthday party on 19 June 2020.

And the police are also investigating a gathering on 13 November 2020 at Mr Johnson's Downing Street flat.

Asked by Labour MPs if he was at that party, Mr Johnson said he would not give a "running commentary" on something that was being investigated by the police.

Ms Gray says she has been "extremely limited" in how much she can say by the Met's inquiries, and she could not publish a "meaningful" report at this stage.

But she does make pointed criticisms of the culture in Downing Street among senior civil servants and staff, adding that some of the gatherings did not observe the high standards "expected of the entire British population at the time", and that too little thought was given to how they might appear to the public.

"There were failures of leadership and judgement by different parts of No 10 and the Cabinet Office at different times," she writes.

"Some of the events should not have been allowed to take place. Other events should not have been allowed to develop as they did."

She adds that the "excessive consumption of alcohol is not appropriate in a professional workplace at any time", likely to be a reference to reports of drunken behaviour in the Number 10 garden and staff filling a suitcase with bottles of wine, and recommends a "robust" policy on alcohol consumption.

The report is crucial to Mr Johnson's premiership, which has been rocked by weeks of damaging headlines about parties in Downing Street and other government buildings.

Many Conservative MPs had said they were waiting for its findings to decide whether to try to oust him from office.

If at least 54 of them submit letters of no confidence to the 1922 Committee, representing backbench Tory MPs, they can set up a vote on his position.

Mr Johnson addressed a meeting of the committee on Monday evening, after which cabinet minister Jacob Rees-Mogg said the "mood was positive".

One Conservative MP who is a long-standing critic of the prime minister said there was little chance of opponents gathering the signatures needed to trigger a vote, but called the party "deluded".

'Didn't get some things right'

In his Commons statement earlier, the PM vowed to learn from Ms Gray's initial findings, saying: "I get it and I will fix it."

"I am sorry for the things we simply didn't get right and also sorry for the way this matter has been handled," he said, as he promised a shake-up of the way Downing Street is run.

Labour leader Sir Keir Starmer said the British people believe Mr Johnson should "do the decent thing and resign" but he is "a man without shame".

The SNP's leader at Westminster, Ian Blackford, was ordered to leave the Commons chamber after accusing the prime minister of lying to MPs about the events.

The PM said he would create a specific Office of The Prime Minister, carry out a review of the civil service code of conduct and bring in measures to improve the way government works.

He faced repeated opposition calls to resign after his statement, and to publish the Gray report in full.

Some Tory MPs backed the PM, but others joined in with criticisms.

His predecessor as prime minister and Tory leader, Theresa May, said: "The Covid regulations imposed significant restrictions on the freedoms of members of the public.

"They had a right to expect their prime minister to have read the rules, to understand the meaning of the rules and indeed those around him to have done so too and to set an example in following those rules."

Former cabinet minister Andrew Mitchell told MPs that the prime minister no longer had his support.

Aaron Bell - reported to be among backbench Tory MPs to be calling for a no-confidence vote - said he had followed strict Covid restrictions at his grandmother's funeral and asked Mr Johnson: "Does the PM think I am a fool?"

Ms Gray was forced to rewrite her report after the Met asked last week for only "minimal reference" to be made to events they are looking at, in order to "avoid any prejudice to our investigation".

The leading investigator, Commander Catherine Roper, said officers had been handed "well over" 500 pieces of paper, and more than 300 photographs so far.

They expect to approach in writing, or via email, individuals "identified as having potentially breached", added Ms Roper.

Downing Street said the PM would "ask Sue Gray to update her work in light of what is found" by the Metropolitan Police, when they have finished their inquiries.

"He will publish that update," added a spokesperson.