Scotland Yard has asked for the Whitehall inquiry into allegations of lockdown-breaking parties in Downing Street to make only “minimal reference” to the events being investigated by police.
The Metropolitan Police insisted officers have not asked for senior civil servant Sue Gray’s report to be delayed or placed any further restrictions on other events.
But the force said it remains in contact with the Cabinet Office team that probed potential Covid breaches in No 10 and across wider Government to “avoid any prejudice to our investigation”.
Boris Johnson continues to anxiously await Ms Gray’s report, which has the potential to trigger a vote of no confidence in his leadership by Tory MPs angered over alleged breaches.
In a statement, Scotland Yard said: “For the events the Met is investigating, we asked for minimal reference to be made in the Cabinet Office report.
“The Met did not ask for any limitations on other events in the report, or for the report to be delayed, but we have had ongoing contact with the Cabinet Office, including on the content of the report, to avoid any prejudice to our investigation.”
The statement indicates that Ms Gray will either have to make significant changes to her report before publication or delay it until after the police inquiry concludes.
Sources close to the inquiry have previously indicated that she was concerned about the prospect of releasing a report that was shorn of some of its key findings.
Officers have not confirmed how many events they are investigating, but reports have suggested it could be as high as eight.
The official inquiry has been long-awaited but its publication was thrown into disarray on Tuesday when Met Police Commissioner Dame Cressida Dick announced that her officers had opened a criminal investigation.
Battling to stay in No 10, Mr Johnson is reportedly considering delaying a rise in National Insurance intended to cover social care reforms and tackle the NHS backlog, in order to sooth backbench Tory anger.
The Prime Minister is also coming under pressure over leaked emails that seemingly contradict his insistence that he did not personally intervene in the airlift of animals from Afghanistan while thousands of people wanting to flee the Taliban were left behind.
So far seven Tory MPs have publicly called for Mr Johnson to quit, but others are believed to have done so privately in letters to the chairman of the Conservatives’ 1922 Committee.
If the number of letters received by Sir Graham Brady hits 54, representing 15% of all Tory MPs, then a vote of no confidence in the Prime Minister’s leadership is triggered.
Mr Johnson would have to then win the support of half of Conservatives MPs in order to stay in No 10.