Polly Toynbee's suggestion that Gordon Brown should quit now and make way Alan Johnson is one that finds increasing favour among Labour MPs and other party figures.
But few believe it will ever happen, simply because they can't see HOW it might come about - how one could get from G to A, as it were.
Let me throw in a couple of theories.
The first was suggested by someone close to David Miliband. This is that at some point Gordon Brown may simply decide to jack it in, knowing that he is taking his party to disastrous defeat.
Unlikely, you may say. But what about Gordon Brown's McAvity quality, whereby in his days as chancellor he used to disappear whenever there was trouble.
A second idea which has been raised is the suggestion that if Brown does go, it should not be this summer or autumn, but at the last possible moment.
That might be AFTER an election is called.
As John Rentoul reminded people a couple of weeks ago, that's exactly what the Australian Labour Party did in the mid 1980s when they replaced Bill Hayden after the election was called, replaced him with the more attractive Bob Hawke, and Hawke duly won the election.
The advantage of replacing Brown late is that it would mean a replacement (such as Johnson) could only be appointed, not elected. And it would enable Labour MPs to hold on to their seats as long as possible.