Police responded to silent alarm during ‘party’ at Downing Street

‘Officers stationed in Downing Street are there to protect against terrorist attacks not check on staff’

A METROPOLITAN Police officer was called out to a Downing Street “party” after a silent alarm was accidentally triggered, the force has confirmed.

The officer responded to the incident along with a member of No 10’s security staff but the alleged illegal gathering was not investigated further.

The officer, who is a member of the Met’s parliamentary and diplomatic protection unit, has been interviewed by Sue Gray, the senior civil servant, as part of her internal investigation into alleged lockdown-breaking gathering in Whitehall. The officer will also be spoken to by his Scotland Yard bosses.

The Met has faced questions over why officers stationed in Downing Street did not intervene in, or report on, alleged illegal gatherings that took place during the pandemic.

Assistant Commissioner Sir Stephen House said it was not the job of armed officers to look for people breaching coronavirus regulations. But he added: “If we find officers knew what was going on and should have intervened we will follow up on that.”

Scotland Yard had previously refused to discuss whether officers stationed in Downing Street were aware of alleged illegal gatherings taking place during lockdown. But under questioning from the London Assembly police and crime panel, Sir Stephen confirmed that officers had knowledge of at least one event.

He said: “One officer was involved in responding with a civilian custodian who works for No 10 to a silent alarm that we believed had been pressed in error.

“That officer has been spoken to both by the Sue Gray investigation and will be spoken to by ourselves.”

It is thought any details of the security call out would have been recorded in the daily police log provided to senior officers. But Sir Stephen stressed that armed officers were stationed in Downing Street to keep the area safe rather than to monitor the activities of staff

He said: “They are not there to check people with No 10 passes or parliamentary passes, they are not checking contents of what they are carrying.

“That is not their job. They are there to protect against terrorist attacks on No10 or people going in and out of No 10.”

He also said the Met’s criminal investigation into the “partygate” allegations was “operating at pace” and he expected it to be completed in the coming weeks.

More than 50 people have received questionnaires from police asking for an account of certain events in Downing Street and Whitehall during lockdown.

Sir Stephen said it was possible more people would be contacted as the investigation progressed.

While most of those facing fixed penalty notices are being treated as attendees, The Daily Telegraph understands that some civil servants are being investigated as alleged organisers.

For large parts of the Covid pandemic such offences resulted in a £10,000 fine – much higher than the Fixed Penalty Notices for attendance, which can be about £100.

Dozens of civil servants are now expecting to be fined, according to a source. “There are people who have accepted that they will get fines.

“Whether they think it was right or wrong, they are resigned to it all,” the insider claimed.

Mr Johnson’s lawyers are believed to have submitted their response to the Met’s questionnaire on Friday.