It's set to be a big day in Westminster as the much anticipated Sue Gray report is due to be handed over.
Prime Minister Boris Johnson is set to receive a copy of the report today, although key details are likely to be missing following a request by Scotland Yard to omit anything they are looking into as part of their own investigation into the alleged parties.
Mr Johnson is due to speak in Parliament at 3.30pm.
Read more: Storm Corrie live
If the report finds he misled MPs about the string of party allegations, then Mr Johnson could be told he is expected to resign or face a potential vote of no confidence from fellow Tory MPs.
Met Police Commissioner Cressida Dick confirmed last week that Scotland Yard is launching its own investigation, but controversially asked Ms Gray to redact anything from her report that is being investigated by police.
Asked about warnings that the inquiry will be a “whitewash” because of the changes, Mr Johnson said: “You are going to have to wait and see both what Sue says and, of course, what the Met says.”
The Prime Minister has publicly said he is “deeply sorry for misjudgements” surrounding events in No 10, but insisted no one warned him a garden party in the first lockdown would be against the rules.
In private, however, he is said to have told Conservative MPs who may oust him as Prime Minister over the saga that he has done nothing wrong.
“You’re going to have to wait and see the outcome of the investigations but, of course, I stick absolutely to what I’ve said in the past,” he said, when asked about those remarks during a visit to a freeport in Tilbury, Essex.
Go here for the latest coronavirus updates and breaking Covid-19 news
But who exactly is Sue Gray and what is she investigating?
Who is Sue Gray?
Sue Gray is a senior civil servant who found herself thrust into the limelight when she chose to step in to lead the investigation.
It comes after her boss, Cabinet Secretary Simon Case, stepped down following allegations that his own office held a Christmas event in December 2020.
The Cabinet Office's second permanent secretary has investigated two Cabinet ministers in the past over alleged wrongdoing.
The subjects of those investigations, former first secretary of state Damian Green and former chief whip Andrew Mitchell, ended up being sacked and quitting respectively.
Ms Gray joined the Civil Service in the late 1970s and once ran a bar in Northern Ireland.
What is she investigating?
Ms Gray is leading an inquiry into possible No 10 lockdown breaches.
The purpose of her inquiry is to establish "a general understanding of the nature" of gatherings that took place and whether any "individual disciplinary action" should be taken, according to the inquiry's terms of reference.
According to the Institute for Government (IoG), Ms Gray’s final document is "set to be a largely factual account about parties that were held in Downing Street".
Catherine Haddon, a senior fellow at the think tank, said the report "may not assign individual blame but might refer disciplinary action to others".
If evidence emerges of behaviour that is potentially a criminal offence, then the matter will be referred to the police and the Cabinet Office’s work may be paused. However, anything considered a criminal offence is likely being investigated by police, so will be redacted from Ms Gray's report.
What could happen?
The IoG states that, while Ms Gray’s findings may "touch on the role of the Prime Minister", it is not her place to "judge his behaviour".
But Dr Haddon said that the "bare facts alone could prove deeply damaging", including in the way the official sets them out and the language used.
It will then be for Conservative MPs and possibly Mr Johnson’s independent ethics adviser – should the Prime Minister commission a separate probe by Lord Geidt – to decide whether he broke the Ministerial Code and misled Parliament.
Mr Johnson has previously said that he has followed coronavirus guidance and, while apologising for not stopping the May 20 gathering, has told the Commons he understood it to be a "work event".
When will her report be completed?
Mr Johnson is expected to receive the report on Monday January 31. He is due to speak in Parliament at 3.30pm.
Downing Street has committed to publishing the report before Mr Johnson addresses MPs, though the Cabinet Office is yet to confirm when it will be handed over and further delays cannot be ruled out.