Scotland Yard on Friday said it has sought minimal reference to the events it is investigating from a UK Cabinet Office inquiry, being led by top civil servant Sue Gray over the so-called partygate scandal of alleged gatherings within government quarters that may have breached COVID lockdown rules in 2020-2021.

Gray's inquiry report, which poses a serious threat to British Prime Minister Boris Johnson's leadership, is said to be complete but there has been a delay since some of its findings were passed on to London's Metropolitan Police earlier this week, to investigate potentially serious and flagrant breaches of coronavirus laws.

It triggered speculation around the publication of the report, with Johnson dismissing Opposition attacks that Downing Street was in any way interfering with the process and promising that he would publish the findings "in full" once received.

"For the events the Met is investigating, we asked for minimal reference to be made in the Cabinet Office report, the Met Police said in a statement, which would indicate that necessary changes may be the reason behind the delayed publication.

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 added.

Anyone found guilty of breaching the COVID rules would be liable to a fixed penalty notice or fine.

On Tuesday, Met Police Commissioner Cressida Dick announced that her officers had launched their own inquiry after being handed information by Sue Gray during the course of her internal investigation. It has been unclear ever since if the police probe would impact the timing and nature of the report's publication.

Ministers indicated on Friday that Downing Street has yet to receive the findings, which means it is unlikely to be released any time soon.

The Opposition Labour Party and also some Tory MPs want the report to be published in its entirety, including the names of those attending and organising gatherings at Downing Street and across government offices in Whitehall during strict lockdowns imposed on the wider public.

Johnson's own participation has been linked with at least two events a garden party on May 20, 2020, and a birthday cake get together for his 56th birthday on June 19 the following month.

The coronavirus lockdown rules in force at the time imposed a strict ban on social gatherings with anyone outside your own household. Johnson has since apologised in the House of Commons and said he believed these were work events.

Meanwhile, calls for Johnson to resign as prime minister continue to linger from the Opposition benches as well as within his own Conservative Party. Most Tories are said to be waiting for the Gray report before deciding whether to submit letters of no confidence in Johnson, potentially triggering a leadership contest.

At least 54 Tory MPs must write to Sir Graham Brady, chairman of the backbench 1922 Committee, to trigger such a vote.