A long-awaited report into lockdown parties and gatherings at Downing Street and Whitehall has been published but in an "extremely limited" form.
Senior civil servant Sue Gray was appointed to look into the gatherings, with her investigation ultimately covering events held on a dozen dates during strict COVID-19 lockdowns in 2020 and 2021.
They included a gathering to mark Boris Johnson's birthday, an event in the garden of 10 Downing Street, several events for departing staff, and a number of other Christmas gatherings in mid-late December 2020.
However, the report contains limited information as police are now investigating a number of the events.
In the report, Ms Gray says: "This necessarily means that I am extremely limited in what I can say about those events and it is not possible at present to provide a meaningful report setting out and analysing the extensive factual information I have been able to gather.
"Given the widespread public interest in, and concern about, these matters, and to avoid further delay, I am providing an update on the investigation and I am setting out some general findings now."
In her findings, Ms Gray said some of the behaviour at the gatherings is "difficult to justify" given the far-reaching restrictions in place during lockdown.
She says at least some of the gatherings examined "represent a serious failure to observe not just the high standards expected of those working at the heart of Government but also of the standards expected of the entire British population at the time".
She also said some staff felt "unable" to raise their concerns about what they saw at work - with Ms Gray saying there should be easier ways for staff to raise such concerns "informally".
The top civil servant has also found that No 10 Downing Street's garden was 'used for gatherings without clear authorisation or oversight', which wasn't 'appropriate'.
In her conclusion, Ms Gray said: "A number of these gatherings should not have been allowed to take place or to develop in the way that they did.
"There is significant learning to be drawn from these events which must be addressed immediately across Government.
"This does not need to wait for the police investigations to be concluded."
Boris Johnson addressed the issue in the House of Commons after the pared-down report was published this afternoon.
He promised to learn lessons and apologised for the way the affair's been handled.
He said: "It's no use or saying 'this or that was within the rules' or that 'people were working hard'... this pandemic was hard for everyone.
Mr Johnson insisted he "gets" the issue and will now fix it.
He told MPs: "I want to say to the people of this country I know what the issue is.
"It is whether this government can be trusted to deliver, and I say 'yes we can be trusted to deliver'."
However, he faced sharp criticism from the opposition over the findings.
The Labour leader Sir Keir Starmer says the update from Sue Gray suggests police are looking into a gathering in Mr Johnson's own flat.
Mr Starmer said: "There can be no doubt that the prime minister himself is now subject to a criminal investigation.
"The prime minister must keep his promise to publish Sue Gray's report in full when it is available, but it is already clear what the report disclosed is the most damning conclusion possible."
Ian Blackford, the SNP's Westminster leader, said Mr Johnson's position was "completely untenable".
He said: "The prime minister is guilty of breaking lockdown rules and misleading parliament. He must resign - or be removed from office."
He accused the PM of lying to the Commons, for which he was ousted from the House by the Speaker.
A number of Tory backbenchers have already voiced their concerns about the parties, with MP Andrew Mitchell today saying the PM no longer has his backing.
Several Conservative MPs had indicated they would wait until Ms Gray's report was released before deciding whether to submit letters of no confidence in Mr Johnson.
Additional reporting by IRN