New Year, new PM: man to watch is Ed Miliband

The Miliband brothers, David and Ed, made a rare joint public appearance today to launch a climate change campaign at the Science Museum. The timing was fascinating for there is excited talk among Labour MPs that either of the two young Cabinet stars could take over the party leadership at the end of the year.

First things first. Labour realists can see that the recent polls carry one obvious message: Labour cannot win a general election while Gordon Brown remains leader. Even those publicly supportive are dismayed at his lack of communication and leadership skills.

There is an increasing feeling that if there is to be change, then it must be generational - which makes Ed Balls and the two Milibands the favourites.

Balls is seen - by Labour backbenchers and the public - as too ambitious, too much of a bruiser, and too closely associated with Brown.

Which brings us to a column written by Rachel Sylvester of the Times this week in which she floated the idea that either Miliband would be good - it doesn't really matter which - and that the puppet-master who might arrange such a thing is, of course, Lord Mandelson.

Mandy is riding high after his Labour conference speech - it saved the week, in most people's view - and is the one person whose withdrawal of support would be terminal for Brown. And guess what Mandy is up to this coming weekend? Visiting David Miliband's constituency to give the annual 'South Shields Lecture' (previous speakers: Tony Blair, Patrick Stewart and David Puttnam). As Rachel Sylvester wrote, "It would be fascinating to hear their private conversation."

Why Sylvester's comments have sparked interest is because she would not have written this piece, it is thought, without encouragement.

One argument against changing the Labour leader has been that the public - ie. the media - would not accept a second coronation without a general election. Brown's unelected takeover of Number 10 was quite enough, thank you. The new leader would therefore be bound to go to the country almost immediately and would be in danger of handing victory to the Tories too cheaply.

But if the changeover were to be left to Christmas/New Year, and the new leader in place by, say, the end of January, then they would probably get away with holding on for a May election, on the grounds that that's what everyone's been expecting, as long as they immediately confirmed the May/June date.

At which point, who knows what might happen? The economy could be showing real signs of improvement - making the public suspicious of the Tory doom-mongering - and the post-Brown bounce could be quite something.

The question is, which Miliband? Many say Ed is likely to defer to his elder brother David. But Ed is seen as more personable and a stronger campaigner than David. Couple those factors with the chitchat in Brussels and Paris that David could become Europe's first foreign minister - sorry, "high representative" - and you see why the smart money is moving in Ed's direction.