As we noted last week, the furore over Partygate has really shone a spotlight on the uneven way in which lockdown and other Covid-19 regulations were enforced.

Cressida Dick’s decision to authorise a one-off retrospective investigation into the goings on at Downing Street is just an especially high-profile example of a broader trend.

It isn’t immediately obvious that the fact that the Metropolitan Police issued 17 times as many fines as their Durham counterparts, as reported in this morning’s Sun, is in the same mould. It isn’t difficult to imagine why the capital might have had more instances of rule-breaking, not least it being much bigger.

But the Conservatives, and their supportive papers, have clearly latched on to the idea that the Durham Constabulary are not doing their job over ‘Beergate’, or the Labour leader’s beer and takeaway with “up to 30 people” last year whilst restrictions were in place.

Richard Holden MP has written to them to demand they re-open their investigation into Sir Keir Starmer, whilst Nadine Dorries says that “no reasonable person believes Labour’s story”.

Perhaps they’re on to something, because the Labour response has not been as assured as it might be. Today’s papers report that Starmer won’t confirm that he’ll cooperate with the police if they do reopen the investigation, and offering a pretty thin excuse for misleading the press over Angela Rayner’s attendance at the event now dubbed ‘Beergate’.

The danger for Starmer is that hypocrisy, or the perception thereof, is one of the most dangerous things in politics. Having struck a very pious note in his (broadly effective) harrying of Boris Johnson over Partygate, the Labour leader is more exposed if it turns out he broke the rules himself.

And having endorsed a retroactive investigation into Downing Street, it isn’t obvious what grounds he would have to object to Durham Constabulary looking into ‘Beergate’.

So we can expect the Conservatives to keep up their attacks as the local elections loom. They may well cause the Labour leader some difficulty, or take some pressure off the Prime Minister.

But if they do, it may only be by even further corroding the image of politics and politicians in the eyes of the public. ‘One rule for them’ might be an effective weapon if the Opposition can turn it on the Government; once it seems to apply to both of them, it’s just a recipe for disenchantment.