Sadiq Khan demands 'explanation' from Met Police after photos of Boris Johnson at lockdown drinks emerge

London mayor Sadiq Khan has written to the Met Police asking for a "detailed explanation" of its partygate probe - after claiming photos showed the PM was "caught red-handed" at an event for which he was not fined.

Mr Khan has asked the Metropolitan Police's acting commissioner Sir Stephen House how decisions were made about whether fines should be issued for lockdown breaches in individual cases.

Earlier, the mayor told Sky News that newly-released photos showing Boris Johnson holding a drink at a leaving do in November 2020 were a "smoking gun".

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A spokesman for the Met said it had nothing to add to the statement issued last week when it said the investigation into lockdown-breaking events in Downing Street and Whitehall had concluded, with 126 cases involving 83 people being referred for fixed penalty notices.

Number 10 said it would not be commenting.

A spokesperson for the mayor - who oversees policing in the capital - said Mr Khan had written asking for an explanation of "the factors which were taken into account by investigating officers when decisions were made about whether to take action in individual cases" in the probe.

"He has asked them to take steps to also reassure Londoners by making this explanation to them directly, because he is concerned that the trust and confidence of Londoners in the police is being further eroded by this lack of clarity," the spokesperson said.

The letter comes after the Liberal Democrats wrote to the police watchdog, the Independent Office for Police Conduct (IOPC), on Monday asking it to investigate the Met Police probe, to establish and make public the process by which detectives reached their conclusions.

Lib Dem deputy leader Daisy Cooper said a lack of transparency was likely to "create considerable public confusion" and that it was hard to understand why some junior members of staff received fines for events attended by the prime minister while he did not.

The IOPC confirmed on Tuesday it had received the complaint and is sending it to the Met, as is legally required, who will then decide whether a referral to the watchdog is required.

The prime minister himself received a fixed penalty notice in relation to a separate gathering on his birthday in June 2020 but at the conclusion of the Met Police probe last week it was disclosed that he had not been fined for any other events.

Grant Shapps, the transport secretary, told Sky News that Mr Johnson was "clearly not" partying in the November 2020 photographs, which were obtained by ITV News.

But Mr Khan told Sky News: "There clearly was a party - he was raising his glass, there were empty wine bottles there... I think the police should be explaining how they reached their conclusions, that's the right thing for them to do.

"Those that broke the rules were fined and here we have a photograph which looks like the prime minister caught red-handed breaking the rules - some would call it a smoking gun."

The pictures emerged ahead of the expected publication this week of the full report by senior civil servant Sue Gray into the partygate affair.

Controversy has been swirling over a meeting between Ms Gray and the PM - details of which were first revealed by Sky News and which Number 10 has now admitted was instigated by its officials, after this account had initially been refuted by ministers.

A source has told Sky News that in the meeting Mr Johnson implied Ms Gray should consider dropping the report.

Number 10 said the prime minister did not ask her to drop the report or not proceed with the report.

Mr Johnson also faces a parliamentary probe over whether he misled parliament, having told MPs after details of the November 2020 event were first made public that "the guidance was followed and the rules were followed at all times".

Sir Roger Gale, the Tory backbencher and long-term critic of Mr Johnson, told Sky News: "What is clear is what was said in parliament at the despatch box: was there a party at Downing Street? Not did you attend one but was there a party at Downing Street on 13 November?

"The prime minister's answer: no. The photograph says: yes."