Mind you safe seats can come unstuck in such circumstances. It's happened several times that Ministers who have lost their seats have been put up as many as two more times in "safe" seats and been beaten. Voters tend not to like that kind of thing - voting for a candidate and having him or her promptly resign. They don't like being taken for granted

I think in the aftermath of an election in which his partyu had won, and he personally had been guven the boot, the chances of Howard being defeated yet again in a "safe seat" would probably be pretty strong...

In which case they could always try sticking him in the House of Lords - the technical position is that the Prime Minister is whoever is called along to curtsy to the Queen, in the expectation that they can form a Government which can get things passed in the House of Commons. They don't have to be in the Commons. I'm not even certain they have to be in Parliament at all, at least in theory...

Perhaps they could call him Lord Protector or something.