It's all a big 'if', isn't it?!
Indeed it is - anyone with a shred of integrity would have already resigned.
Do you really think he is going to resign?
He's clearly not going to go easily. The police questionnaire may well be a lose/lose bear trap. Answer yes and he'll be fined (effectively a conviction) and it is difficult to see how he survives this. Moreover if he accepts a fine he will have, effective, admitted that he lied to parliament, which is a resigning issue. Try to claim he wasn't there, it wasn't a party etc etc and he runs the risk of going down the Chris Huhne route - it wasn't the speeding fine that got him, it was perverting the course of justice that did for him by claiming his wife was driving. So if Boris lies on the questionnaire the sanction might not be just a fine, but jail time as perverting the course of justice is a much more serious offence than speeding or partying during lock-down.
MPs have not put forward a vote of no confidence, have they.
Yet - I suspect they are planning the optimal moment. Currently it is still easy to 'wait and see' - the time to strike, I imagine will be when (if) he is found guilty of breaking the lockdown law. And remember that those plotting against him don't just need to trigger a VONC - they need to win it. They will want the actual vote to take place when their colleagues cannot be in 'wait and see mode'.