The decision of the Metropolitan Police to investigate allegations of lockdown rule-breaking in Downing Street was a long time coming. That it was announced just minutes before the Commissioner, Dame Cressida Dick, was due to appear before a Greater London Assembly policing committee suggests she felt her prevarication was hard to justify.

Many people have been fined for breaking the rules, with party organisers facing particularly harsh penalties. Why should No 10 staff, or even the Prime Minister, be treated any differently? In the immortal words of Thomas Fuller, “Be ye ever so high, the law is above you”.

The Met’s involvement cast doubts over the timing of a report by Sue Gray, a senior civil servant, into the No 10 parties. Downing Street initially said it would be delayed but appeared to soften that position. It would suit Boris Johnson if he could put some distance between the recent flood of party allegations and any findings of culpability, criminal or otherwise.

But this needs to be brought to a speedy conclusion for the good of the country. If the police have no objection to Ms Gray’s report being published (in full) when it is concluded there need be no further delay. Equally the police should expedite their investigation, not let it drag on for weeks, involving dozens of officers who have better things to do.

While breaking the regulations is a serious matter given the sacrifices others made to stick within them, the punishment for failing to do so normally warranted no more than a £100 fixed penalty. Breaches did not require full-blown investigations to establish and there is no reason why the Downing Street goings-on cannot be dealt with in a summary manner.

Mr Johnson said he was happy to be questioned by the police but Labour said the very existence of an investigation meant Mr Johnson should stand down immediately. That was not a position it took when Tony Blair’s Downing Street operation was investigated in 2007 during the “cash for honours” affair.

Moreover, there are pressing issues confronting the country that need stability, not least the threat of war in eastern Europe. The great danger of “partygate” is that it is a huge distraction from the day-to-day requirements of governance.