The Cabinet Office is weighing up when to publish its partygate report in the wake of the Metropolitan Police asking for "minimal reference" to be made to the events it is investigating, Sky News understands.
Sources have confirmed that Sue Gray, the senior civil servant leading the inquiry into a series of events in Downing Street and across Whitehall which are alleged to have broken COVID-19 lockdown rules, will comply with the Met's request.
She is now assessing whether she is in a position to finish the process or whether there will now be a delay.
Gray put in 'invidious position'
It is understood Ms Gray's team have not ruled out finalising a version that passes muster with the Met. Whatever is published will take into account the force's latest statement.
Sky's political editor Beth Rigby notes that this amounts to an invidious position for Ms Gray, who has to decide whether to put a partial version of her report out now, or wait until the police investigation is complete.
Her report, which is likely to have a significant impact on Boris Johnson's future as prime minister, has not yet been delivered to Number 10.
The Met announced earlier this week it was investigating a "number of" gatherings in 2020 and 2021 for potential breaches of COVID regulations.
In its latest statement released on Friday, the force 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."
Officers are currently investigating possible breaches of COVID rules that could warrant fixed penalty notices rather than more serious offences, according to the PA news agency.
Westminster has been braced for the publication of the Gray report, but this latest police statement throws the timing of that into doubt.
Politicians and legal figures question Met's move
Some legal figures have questioned the rationale behind the force's request.
Reacting to the statement, SNP Westminster leader Ian Blackford said the report "must be published in full and undoctored without further delay".
"People are understandably concerned that this increasingly looks like a cover up," he said.
This criticism was echoed by the Liberal Democrats, with the party leader Sir Ed Davey telling Sky News the delay is an "utter fiasco and it's got to stop".
Sir Ed said he is "worried about any growing perception of a stitch up" between the government and the leadership of the Metropolitan Police.
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Labour leader Sir Keir Starmer said he wanted to "see Sue Gray's report in full and the investigation finished as quickly as possible", claiming the government is "paralysed" by the ongoing police investigation.
Asked whether, given he was previously director of public prosecutions, he saw any issues of prejudice, Sir Keir said: "Any issues of prejudice have got to be worked through but this whole mess, this whole paralysing of politics, is being caused by the prime minister and his wrongdoing."
Fran Hall, a spokesperson for the COVID-19 Bereaved Families for Justice campaign group who lost her police officer husband to COVID, said the Gray report has "turned into a circus".
"Tragically, it seems here that the Metropolitan Police have broken the trust of the public by first refusing to investigate flagrant law breaking, and now demanding any other investigations hide the most serious illegalities happening at Downing Street," she said.
"It's incredibly painful and they have let families like mine down. My husband was completely committed to justice, and he would have been appalled by this."
Have internal disagreements led Met to change position?
When a police investigation into partygate was launched on Tuesday, the Met briefed journalists that they did not believe the full publication of the Gray report would prejudice their own investigation.
That position changed on Friday morning, with the force now requesting only "minimal" reference be made in the Gray report to events they are examining.
According to Sky's deputy political editor Sam Coates, senior officers are pointing towards an internal disagreement as the reason for the change.
He understands the police officers involved in the actual investigation have made it clear they object to the release of the full report, and insisted the force change its position as a result.
Number 10 says it hasn't asked Gray to go back to the Met
Downing Street said it has not asked Ms Gray's team to go back to the Met to make sure her report does not interfere with the police investigation.
A spokesman for the PM said: "No, you'll be aware that the terms of reference clearly set out that the Cabinet Office would keep in contact with the police and again it's an independent investigation.
"We haven't been privy to the details of that investigation or any of its content. So that would be a matter for the investigations team and the Met."
Asked if Number 10 had spoken with the Met about the Gray report and what could be published, the spokesman told journalists: "Not that I'm aware of, no."
Asked if it was correct that the Met's announcement had no involvement from No 10, he said: "I believe that's correct."