Sue Gray's report into the Downing Street parties was published at 11:25am today, less than an hour before Prime Minister's Questions, sparking fiery scenes in the House of Commons when Boris Johnson addressed MPs.
Ms Gray's report investigated numerous events that took place within Downing Street while the nation was under varying degrees of Covid restrictions.
Critics of Mr Johnson have used the report to call for him to resign, including members of his own party. However, most Conservative MPs have remained loyal to the Prime Minister on what is a tumultuous day in Westminster.
Here is everything you need to know about Ms Gray's Partygate report:
Boris Johnson raises a glass at a Downing Street party. GOV
The report concluded that many of the events investigated "should not have been allowed to happen", some of which were attended by "leaders in Government".
It also noted that "the public have a right to expect the very highest standards of behaviour" inside Government and "clearly what happened fell well short of this".
Of the parties Ms Gray investigated, a number of them included "excessive" consumption of alcohol.
One such party, on June 18, 2020, involved a karaoke machine, pizza, and prosecco. It led to one member of staff being sick as well as fight, with the last person leaving after 3am.
At another party, on December 18, 2020, Downing Street officials accidentally activated the panic alarm during "Wine Time Friday". A cleaner who tended to the room the next morning noted that red wine was spilled on one wall and on a number of boxes of photocopier paper.
Ms Gray abandoned her investigation into the "Abba party" held in Boris Johnson’s flat despite finding that alcohol was present on the evening Dominic Cummings was forced out of Downing Street.
Former aide to the Prime Minister, Martin Reynolds, was warned on WhatsApp of "comms risks" around a number of parties.
Mr Reynolds also suggested that No 10 staff had "got away with" a large gathering on May 20, 2020.
Boris Johnson said he takes "ultimate responsibility" for No 10's failings during the Partygate scandal, in response to Ms Gray's report.
"I haven’t broken any rules and any attempt to compare a perfectly legal takeaway while working to this catalogue of criminality looks even more ridiculous today," Sir Keir Starmer told Parliament in response to the report.
GB News presenter Nigel Farage expressed his outrage at the Government following the release of the Sue Gray report, tweeting: "The Sue Gray report tells me that there is no accountability left in public life in this country. The PM will continue in office and the party will hit the rocks at the next election."
SNP Westminster leader Ian Blackford called on Mr Johnson to be ousted following the publication of Ms Gray's report addressing Conservative MPs: "If they don't remove this Prime Minister, how will they ever look their constituents in they eye ever again?"
Former minister Tobias Ellwood was heckled by Tory MPs for saying: "This is a damning report about the absence of leadership, focus and discipline in No 10 – the one place where you expect to find those attributes in abundance. I’ve made my point and my position very clear to the Prime Minister: he does not have my support."
Liberal Democrat 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."
Boris Johnson says he's "appalled" by the behaviour highlighted in Ms Gray's report.
The Prime Minister tells GB News' Tom Harwood that Covid rules had to be implemented.
Scottish Tory leader Douglas Ross said: "If they reach a conclusion that the Prime Minister deliberately and intentionally went to the House of Commons to mislead people, then the ministerial code is actually very clear. The expectation is that the Prime Minister or any minister should stand down.
Boris Johnson is meeting the 1922 Committee of backbench Tory MPs - he was met with the customary banging of tables upon arrival.
Tory MP Julian Sturdy has called for the Prime Minister to resign following the release of the Sue Gray report.
A Tory party source said it would be "ludicrous" for Boris Johnson to resign in the wake of the Sue Gray inquiry.
Boris Johnson had been keen to emphasise that No 10 was not like a “Saturday night in July in Ibiza”, according to a Conservative Party source.