What is the PM's defence to the charge he attended illegal parties?

The presumption of many MPs - and maybe many of you - is that the Met is bound to issue a fixed penalty notice to the prime minister for attending parties in Downing Street, because the half dozen "events" he attended look, swim and quack like a party, and therefore must have been a breach of Covid rules.

So what is Boris Johnson's defence? He thinks he has one, so he is paying out of his own pocket for a lawyer - who is also being used by his wife Carrie Johnson. And the Met Police have sent the relevant questionnaires for the PM and Carrie direct to this lawyer.

As you know Boris Johnson's consistent claim is that he thought and was advised that the events he attended were "work", not illegal parties. But what would "prove" that these were work, not parties?

I am told that the relevant test - or at least so his lawyers believe - is whether he went back to "proper" work immediately after drinking a glass of wine in the Downing Street garden or being ambushed by birthday cake in the cabinet office, or saying goodbye to a colleague in a haze of prosecco or singing along to Abba in the study of his Downing Street flat.

If he can prove that he didn't get drunk and incapacitated, and has proof that he resumed more conventional prime ministerial activities after the seeming parties, his legal advisors seem to think there is a chance he can prove said events were simply part of his working day.

And if he got sozzled and went for a kip, he'd be fined.

If this legal advice is right, it's all about what evidence his lawyer can supply to the police about what he did after the gatherings.

What's more, the PM apparently thinks he can even defend being in his Downing Street residence when Abba was playing on the night that his aides Dominic Cummings and Lee Cain were evicted - because he will say he was in his study with officials plotting how to replace them, and that would have been work.

Now for the avoidance of doubt, if this were the court of public opinion, the question of whether his digital records and diary show he went directly from boozing to working would be irrelevant. As I said, most of the country thought all socialising with drinks was banned, and is deeply unsympathetic to the idea there was a work loophole.

Also, for the avoidance of doubt, plenty of respectable lawyers think the idea of a work loophole is for the birds.

But I am relaying why the PM is going to the bother of paying for a defence.

Will it work?

I slightly doubt it.

Those close to him think he will be fined. And much of the work of his team is to prepare the political case to put primarily to his MPs - and the public - for why he shouldn't resign or be booted out if he is fined.

How long have they got to develop the argument that he should stay in office despite a seemingly clear breach of the ordinance in the ministerial code, that all ministers of the crown need to adhere to the highest standards of probity?

A few weeks yet.

Apart from anything else, those who attended the party-like events in Downing Street and the Cabinet Office are still receiving their emailed questionnaires. The PM got his on Friday night. But others have been notified they will receive questionnaires but haven't had them yet.

So at the earliest, the Met will get all their questionnaires back a week from tomorrow, since everyone who is sent one has a week to complete it.

And then it will take a few weeks for the Met to decide whether booze, sausages rolls and cake are the tools of work - as the PM hopes, perhaps optimistically - or the very definition of a party that breached the Covid rules.