Carrie Johnson has become embroiled in the partygate scandal over allegations that two of her friends visited the flat she shares with her husband Boris, according to reports.
The official inquiry into allegations of parties in Westminster has been widened to include socialising in the prime minister’s own flat.
Sue Gray, the senior civil servant leading the investigation, has reportedly received evidence that Henry Newman and Josh Grimstone entered the property on several occasions.
According to the Sunday Times, the pair claim to have visited the flat for work-related reasons.
However, both were based in the Cabinet Office rather than No10 at the time.
A government source confirmed to the paper that the “scope of the inquiry has broadened” to include the alleged visits by Newman and Grimstone.
However, a Whitehall source said: “Why are two spads [special advisers] from the Cabinet Office going to the PM’s flat to have work meetings with the prime minister without any officials present? It doesn’t pass the sniff test."
Meanwhile, The Observer reports that Ms Gray has been granted access to security data showing staff movements in and out of the building – including information from swipe cards.
Ms Gray is carrying out inquiries into at least nine alleged gatherings at Downing Street and across Whitehall in 2020.
Her findings are expected to be published in the coming week.
Deputy Prime Minister Dominic Raab has said Tory MPs are rallying behind Boris Johnson ahead of the publication of the high-profile report.
“There is a rallying of support behind the Prime Minister, you could feel it in the chamber,” Mr Raab told the BBC’s Sunday Morning programme.
“I think the reason is the booster campaign has been so successful, we are coming out of the lockdown measures, we are opening up the economy. These are all because of the calls the Prime Minister has made.”
Mr Raab refused to be drawn of whether the findings of Sue Gray would be published in full, although he insisted there would be “full transparency”.
“The process for it will be for the Prime Minister to decide,” he said.