What is the investigation into staff gatherings in No 10 Downing Street? The inquiry was launched last year after allegations emerged about a series of parties in Downing Street in the winter lockdown of 2020, including a Christmas party and a leaving do, as well as a drinks event at the Department for Education. Initially, it only covered these three events and was due to be conducted by cabinet secretary Simon Case. Why did the prime minister order an inquiry? Boris Johnson ordered Case to investigate because he was coming under political and public pressure over the parties. No 10 believed commissioning an investigation would help to draw a line under the affairs. However, with more revelations about gatherings and the prime minister’s own involvement, the scope of the inquiry has kept swelling and implications become more serious for Johnson. Why is Sue Gray now in charge and who is she? When it emerged that the private office of Simon Case may have had their own gathering, Johnson handed over responsibility to another senior civil servant. Sue Gray, currently second permanent secretary in the Department for Levelling Up, Housing and Communities, was formerly head of propriety and ethics in the Cabinet Office and is known for carrying out such work. She has a fearsome reputation, with some praising her fairness and others claiming she works in an untransparent manner. What is she now investigating? The terms of reference still only mention three parties but the remit has now widened to cover up to 16 alleged gatherings, including two in the garden of No 10 in May 2020 where the prime minister was in attendance for a short time, and two held by No 10 staff on the eve of the Duke of Edinburgh’s funeral in April 2021. How and when will the report be published? Gray’s findings will next week be handed to the prime minister, who commissioned the inquiry. They are likely to be statements of fact, and will not include accompanying evidence such as transcripts or correspondence. Johnson will be given advance sight of the summary and then he will be expected to make it public and give a statement to the House of Commons. Will she make a judgment on wrongdoing? Government sources say Gray’s findings will be factual, but it is possible they could edge into finding a factual breach of guidelines or even the law. However, the terms of reference say any suspected criminal wrongdoing would be handed to the police and the inquiry would be paused – which so far has not happened. As for any disciplinary action as a result of the findings, that is a matter for the Cabinet Office if it relates to No 10 staff, or the prime minister if it relates to ministers – including himself. Johnson could end up referring the findings to Lord Geidt, the independent adviser or ministerial interests, if his own conduct in relation to the ministerial code is questioned by Gray. What will the political consequences be for Johnson? Johnson’s political future is riding on the Gray report. If he comes out of it badly, MPs could well launch a leadership challenge against him by submitting letters of no confidence in him to Sir Graham Brady, the chairman of the 1922 Committee of backbenchers. If it finds Johnson behaved unwisely or foolishly, without saying or implying that he broke the rules or ministerial code in terms of his openness and honesty, then it is possible that he may avoid an attempt to topple him. Numerous Tory MPs have made clear they are awaiting the outcome of the report before they decide whether to continue backing Johnson as prime minister or not. Either way, there is a huge amount riding on what Gray says.