Why Tory MPs are split in their loyalty to Boris Johnson ahead of Sue Gray report publication

Why the delay to publishing the Sue Gray report could be positive for the prime minister, explains ITV News Deputy Political Editor Anushka Asthana

The case of the missing Sue Gray report is causing some frustration in Westminster - not least because of briefing earlier in the week that it was finished and ready to go to the PM.

First it was "expected" on Wednesday, then Thursday and now - who knows?

The subject of the delay is clear - it's the checking process that the document needs to go through, not just with lawyers within government, and HR - given the potential consequences for staff - but also the Met Police. 

Sources insist that even if there wasn't an active police investigation, officers would have scrutinised the content to make sure nothing published would scupper future investigations.

But with one already underway, it's even more sensitive. 

Cressida Dick confirms an investigation has been launched:

The worry for Johnson's critics - is that the result of the checking process is to ultimately sanitise the report - and take out its most explosive content.

And that, of course, matters a lot. 

Because the PM's future is hanging on the content of this report that he has begged his MPs to wait for. 

There are some - perhaps enough to take the total of no confidence letters over 54 - who won't really care either way.

They are already convinced by media revelations that Johnson has gone too far and as long as Gray confirms those allegations they will say he should go.

They've waited for the report but it's unlikely to change their minds (although a number have held back because they worry he will still win a confidence vote and then be safe for a year). 

But others are in a very different position. One senior backbencher - who I wouldn't describe as a fan of Johnson's- said they would only take action if Gray delivers new "explosive" revelations beyond those already in the press.

Others are now active members of the Johnson "Support Group" WhatsApp that I've written about before. Some are joining meetings strategising how to save the PM.

I bumped into one minister in that group he said he was convinced the mood had changed. 

There were three things he pointed to arguing they have actually helped Johnson: first Christian Wakeford's defection to Labour that rallied Tories to work together; second the comments by David Davis calling on him to go; and weirdly the police investigation.

"No one can accuse them of lacking independence," he said (also knowing there is a higher bar in a police investigation looking for criminality than a civil service one looking at the question of ethics). 

So for some it could potentially buy more time in which Johnson could try to appease Tories with policy shifts. 

All that said - there are a lot of Tory MPs furious with the PM- and others who say the situation is "beyond grim.

The 54 could easily be hit and followed by a confidence vote in which dozens could vote against the PM.

Perhaps a majority but most think that has become less likely.

But even if he wins, as we've seen with Theresa May a confidence vote is deeply destabilising and usually marks the beginning of the end - if not the end itself.