Boris Johnson has insisted he will not seek to block names appearing in the Sue Gray inquiry report into partygate and said he is “looking forward” to seeing its contents “pretty soon”.

The Prime Minister said he was “very grateful” for the Metropolitan Police’s investigation, which concluded with 126 fines for lockdown breaches in Downing Street and Whitehall.

There were demands for answers over how Mr Johnson escaped with just one fixed-penalty notice (FPN) despite being believed to have been present at multiple rule-breaking events.

Potentially damaging further details, including the names of some of those who attended gatherings, will be published in the report from senior civil servant Ms Gray.

Sources close to the investigation expect it will be published early next week, with individuals whose involvement will be mentioned to be contacted over the weekend.

Mr Johnson declined to apologise again for the rule-breaking in No 10 during a visit to Hilltop Honey’s factory in Newtown in Powys, Wales, on Friday.

Instead, he said: “I’m very grateful to the Met for their work, I’m thankful for everything they’ve done.

“We just need to wait for Sue Gray to report, fingers’ crossed that will be very soon, and I’ll be saying some more next week.”

Asked if No 10 would be blocking any names from appearing, he said: “That will be entirely up to Sue Gray and I’ll be looking forward very much to seeing what she has to say, and fingers’ crossed that will be pretty soon next week.”

Officials impacted by the Gray inquiry, including those to be named, are being written to so they can have a chance to respond before the current draft is finalised for publication.

Mr Johnson is among those who will receive a letter from the Cabinet Office team, but No 10 sources declined to say whether it has been received.

The investigators are understood not to be including the full details of the allegations in the letters, but instead are giving a “gist” of the relevant sections to those being contacted.

There were calls for Scotland Yard to explain how Mr Johnson received just the one fine, for his 56th birthday gathering in June 2020 when indoor mixing was banned.

Former director of public prosecutions Lord Ken Macdonald warned “it’s very difficult for us to disentangle exactly how the police investigation has proceeded and how fair it’s been”.

He told BBC Radio 4’s Today programme: “I think without the police providing an explanation for that it’s very difficult for us to understand why they came to the conclusions that they did.”

The crossbench peer said it was not known why the Prime Minister was fined for his presence at what was deemed one of the less serious events but not others.

There has also been no explanation as to why Cabinet Secretary Simon Case, who had to recuse himself from running the civil service inquiry after reports of a Cabinet Office Christmas party surfaced, has not been fined.

“This was a major scandal at the heart of Government, at the heart of the civil service, and we remain very much in the dark about who was involved, who organised the parties, and who was responsible,” Lord Macdonald, who led the Crown Prosecution Service between 2003-2008, said.

“Of course the Prime Minister and the head of the civil service are ultimately responsible, but there plainly were other people as well who were involved in this and we simply don’t know who they are, and I think that’s not good enough.”

Closing its investigation on Thursday, Scotland Yard said a total of 83 people had received at least one fine each for attending events over eight separate days.

One source close to the Gray investigation said the inquiry could be published as soon as Monday, but it was thought Tuesday or Wednesday were more likely.

But ultimately its publication is being handled by No 10.

The Metropolitan Police declined to identify anyone in its £460,000 investigation.

A team of 12 detectives examined 345 documents, including emails, door logs, diary entries, witness statements and 204 questionnaires.

They also examined 510 photographs and CCTV images.

Mr Johnson, his wife Carrie Johnson, and Chancellor Rishi Sunak were all fined over the birthday gathering.

But both Johnsons were told by police they face no further action, according to Downing Street, and Mr Sunak has not received an additional fine.

The Met said 28 individuals had received between two and five fines.

Liberal Democrat leader Sir Ed Davey said if the Prime Minister would not resign over the partygate scandal, Conservative MPs should “grow a backbone and get rid of him”.

Launching his party’s by-election campaign in Tiverton and Honiton, he told the PA news agency: “If they don’t, frankly I hope the voters punish the Conservative Party for treating the voters like fools.”