My issue with this is the dissembling that the PM is doing.
You can call a 'party' a 'works event', but that is just semantics, and it shows an unwillingness to accept the situation for what it was, and deal with it.
As far as i am concerned, you can call it a Teddy Bears' Picnic, the issue is not what it was called, but what it was -
A group gathering at unsafe distances among unrelated people breaking every single Covid Rule put in place by the very organisation whose employees were attending.
It looks as though they felt the rules simply did not apply to them - the PM included, whether he attended for five minutes, or all night is not the issue.
It's the fact that he attended at all that is the issue here.
They can, and will dissemble more, and wriggle, and make noises, but the facts remain, the government is staffed by some who are hypocrites, and run by someone who is one as well.
It is not acceptable, and the PM should resign.
He won't, but he should.