Gordon Brown's resignation puts the cat among the pigeons: O Dave, where is thy victory?

Every day another surprise, every day another wild card is played. Firstly the predictions of a nice smooth Lib-Con coalition deal which dominated this morning – and William Hague sounded so optimistic as to be almost human. Then there were clear signs that it had All Gone Wrong, and that the projected marriage would not now take place. So the Lib Dems had to turn to Plan B. Everyone had predicted that this would founder on Mr Clegg’s unwillingness to do a deal which would allow Mr Brown to remain Prime Minister; and so Labour cunningly unlatched the door in advance of Clegg’s battering ram. Gordon came up with a surprisingly gracious promise of resignation, and suddenly all the balls are up in the air again.

Obviously this is to some extent a move by the Lib Dems to pressure the Tories into upping their offer. But it has raised a whole new possibility, of what the Prime Minister called “a progressive coalition”. As a “coalition of losers” aimed purely at propping up a desperate lame-duck Prime Minister, this would have looked unattractive: but an association of the anti-Tory parties, representing almost 60% of the popular vote, is a different matter. I’m not sure it’ll really work, as the arithmetic is a bit stretched and any such government could be held to ransom either by small parties or by a handful of Labour or Lib Dem dissidents, but it’s a good idea to throw into the mix.

And where does this leave Dave and his myrmidons? I have said that Gordon Brown’s resignation statement was gracious, but it wouldn’t have been Gordon if it hadn’t contained a couple of subtle barbs. Brown acknowledged that Labour’s failure to achieve an absolute majority must be seen as a judgement on him: the subtext is that Cameron’s failure to achieve one must be seen in the same way. He may now have to choose between giving in to more Lib Dem demands than he is comfortable with and being left swinging in the wind. In the latter case, his only consolation will be that this may be a good parliament to be in opposition in.

And now whither Labour? The PM has said that his colleagues should refrain from campaigning for the leadership for the time being, and that he himself will not be supporting any candidate. Pinches of salt are being consumed all over the country, in my case with lime and tequila. But in principle that is sensible enough: before choosing a leader the party would prefer to know whether they are electing the all-things-to-all-persons leader of a rainbow coalition or an abrasive opposition street-fighter.

Gordon Brown has not yet resigned: he has merely announced his intention to resign. He won’t be able to go back on that, but the timescale is fairly loose; there won’t be a new Labour leader until September, which means another four months of Gordon as Prime Minister. Unless he plays another wild card, by offering Nick Clegg the job to seal the deal. Sounds unlikely, but we are suddenly in a zone where anything is possible.