The details of what went on include:

*  Wine, cheese, beer and pizza being provided

*  Someone drinking so much they threw up

*  A karaoke machine being commandeered

*  A "minor altercation" between two people - in other words, some sort of dust-up

*  Staff leaving the building in the middle of the night after parties

*  "Wine Time Friday"

*  Staff clubbing together to buy a fridge to store wine in at work

In plenty of workplaces this sort of behaviour would be unconventional even during normal times.

This, remember, occurred during a pandemic.

Emails and WhatsApp messages revealed by Ms Gray show it was known at the time that what was happening was wrong.

"We seem to have got away with" it, says the prime minister's principal private secretary Martin Reynolds in one. Well, it turns out he didn't.

This was one of Boris Johnson's most senior advisers, hired for his judgement.

On Wednesday, the civil service's chief operating officer, Alex Chisholm, and Cabinet Secretary Simon Case - who was removed from doing the investigation Ms Gray ended up carrying out because there'd been a party in his own office - wrote to civil servants.

Mr Case had let it be known earlier in the day that he wasn't resigning and hadn't been sacked.

In their letter, he and Mr Chisholm talk about taking "the time to reflect on the report in full and consider the issues [the Gray report] has highlighted" and say that "steps have also been taken to strengthen the corporate leadership across the Cabinet Office and No 10".

Some civil servants said they were "absolutely appalled" by what they regarded as the "tone-deaf" nature of the communication.

Anger and embarrassment

So where does all this leave Mr Johnson?

He apologised and, pointedly, went out of his way to explain why he believed he had not knowingly misled the Commons in his previous accounts of what happened.

This is crucial, because being proven to have intentionally lied to the House would cost him his job.

But the prime minister added that he didn't think, at the time, he'd done anything wrong at the event that led to him being fined by police.

And he said he had been right to drop into various leaving dos, even though the police fines would suggest many of them were in direct contravention of the very Covid laws he had championed.

Mr Johnson enjoys a drink at a leaving party in November 2020

Mr Johnson apologised when speaking to Conservative MPs privately at a meeting, but there is deep anger and embarrassment among many Tory MPs over what has happened. They know much of this can't be easily excused or wished away.

And they have the power, collectively, to decide whether he stays or goes.

A 17th Tory MP has now publicly declared Mr Johnson should stand down; others have demanded this privately.

But the vast majority of public critics today are those who've long condemned the behaviour he presided over - and it would take 54 declaring a lack of confidence in Mr Johnson to trigger a vote on his leadership.

Messages

Away from what's going on in public, here's a wee peek at some of the texts I've had from Conservative MPs reflecting privately on where things are and how they judge the mood among their colleagues.

"Think Gray wasn't the bombshell the PMs detractors were looking for," one says. "If anything the photos [shown in the report] look less like parties than we thought they would!"

Another comments: "Yes, I think he'll survive. He did v well in chamber."

"It doesn't really tell us anything newly incriminating. I sense general disinterest to be honest," says one.

Asked if the PM was safe, one backbencher replies: "In my view, yes."

'Very tedious'

Plenty of cabinet ministers have publicly expressed their loyalty to the prime minister.

One told me the drip-drip of revelations in recent months had become "very tedious" and they didn't think "it will affect Boris any more".

Mr Johnson's supporters also delight that there is "no longer a prince over the water", as one senior figure put it to me - in other words, an heir apparent. That was a reference to the chancellor's recent awkward headlines about his wife's tax bill.

But other Tory MPs fret that, from their perspective, too many people's view of the prime minister has been irreversibly set by what has happened and that will make winning a general election very difficult.

It'll take some time for views to solidify and two imminent by-elections, in Wakefield in West Yorkshire and Tiverton and Honiton in Devon, might help do that one way or another.

But it appears Boris Johnson is safe - for now.