The Metropolitan Police is launching an official criminal investigation into “a number of” breaches of Covid-19 rules that took place at Downing Street and Whitehall over the past two years.

Speaking at a meeting of the London Assembly police and crime committee on Tuesday morning, Met Commissioner Dame Cressida Dick confirmed that police were now looking into the issue following information provided by the Cabinet Office.

She said: “What I can tell you this morning is that, as a result firstly of the information provided by the Cabinet Office inquiry team and, secondly, my own officers’ assessment, I can confirm that the Met is now investigating a number of events that took place at Downing Street and Whitehall in the last two years in relation to potential breaches of Covid-19 regulations.

“My officers have assessed several other events that appear to have taken place at Downing Street and Whitehall. On the available information, these other events are assessed as not reaching the threshold for criminal investigation.

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“Throughout the pandemic the Met has sought to take a proportionate approach. I should stress that the fact we are now investigating does not, of course, mean that Fixed Penalty Notices will necessarily be issued in every instance and to every person involved. We will not be giving a running commentary on our cu4rrent investigations, but I can assure you that we will give updates at significant points as we would generally do.”

While the Commissioner said that the Met would not normally retrospectively investigate breaches of Covid-19 regulations – the punishment for which is a fine – she confirmed that there were four factors that would lead to an investigation.

Those are if there is evidence and “not just somebody saying something”, if there is evidence that those involved knew or “ought to have known” that what they were doing was an offence, if there is “little ambiguity around the absence of any reasonable defence”, and if not investigating would “significantly undermine the legitimacy of the law”.

Following the announcement that a criminal investigation is being launched, Mayor of London Sadiq Khan issued a statement in which he said that “no one is above the law” including the Prime Minister.

Mr Khan said: “I welcome confirmation that the Met Police is investigating a number of events that took place at Downing Street and Whitehall in the last two years in relation to potential breaches of the law.

“The public rightly expected the police to uphold the law without fear or favour, no matter who that involves, and I have been clear that members of the public must be able to expect the highest standards from everyone, including the Prime Minister and those around him. No one is above the law. There cannot be one rule for the Government and another for everyone else.”