The publication of the Sue Gray report into “partygate” is expected to be followed by a clearout of some key officials from Downing Street, a plan reportedly referred to by the prime minister as “Operation Save Big Dog”. Oliver Dowden, the Conservative party co-chair, in effect confirmed this on Sunday when he said there was a need for a “change of culture” in the building. Many Tory MPs believe Boris Johnson himself is the person who most needs to go, but he hopes that if others take the blame he might be able to draw a line under the affair. Here are some of the officials most at risk. Martin Reynolds As Johnson’s principal private secretary (PPS), Reynolds is the civil servant with most influence over the prime minister’s day-to-day decision-making. (It’s the Bernard role from Yes Minister.) A career Foreign Office official, Reynolds did the same job for Johnson when he was foreign secretary before becoming ambassador to Libya. He is in the line of fire particularly for sending the email inviting staff to the “BYOB” party in the No 10 garden on 20 May 2020. Stuart Glassborow A former Treasury official who serves as deputy PPS, Glassborow is also in line to leave alongside Reynolds, according to some reports, as part of a planned overhaul of the private office. Dan Rosenfield A former PPS at the Treasury, who worked for Alistair Darling and George Osborne, Rosenfield left the civil service for investment banking but was lured back to Downing Street in late 2020 to be chief of staff, filling the gap left by the departure of Dominic Cummings and Eddie Lister. Since then, he has been the subject of negative briefing from colleagues who find his manner imperious, and he has failed to curb Johnson’s chaotic tendencies. He is blamed for approving the claim that no parties were held at No 10. Jack Doyle A former Daily Mail journalist, Doyle started working for Johnson in Downing Street in 2020 and he took over as director of communications last year, following the departure of Lee Cain and then James Slack. Many of the reports about the drinking culture at No 10 have centred on the press office, where a wine cooler was reportedly installed to facilitate “wine-time Fridays”, and last month it was claimed Doyle had offered to resign after ITV revealed he had given a speech at a lockdown-busting Christmas party on 18 December 2020. At the time, No 10 said the prime minister still had full confidence in Doyle.