Since his ennoblement and return to the Cabinet Lord Mandelson has held the future of the Labour party in his hands. This obviously makes the Business Secretary the most powerful person in the whole labour movement and gives him the power of king-maker. Because of this Mandelson is the only one to watch when it comes to Labour’s succession.

If reports in today’s papers are correct, then Mandelson could be about to shift support away from Brown into David Miliband’s direction.

John Rentoul has spotted this “slightly quixotic” brief letter from Labour MP Colin Challen :

“Perhaps Labour could avoid a generation out of power with the following calendar: 23 November, election of a new PLP chair is a signal that there is sufficient feeling that Gordon too has to go; 30 November, sufficient signatures gathered, Gordon goes; party recognises need for quick leadership election, new leader installed by 21 December; one month to show off new cabinet and launch one Tory-busting cruise missile of a new policy; dissolve parliament 28 January, election day 18 or 25 February. Labour’s bounce leaves it as largest party, possibly with Ed Miliband as PM. What are the odds?”

While the timetable does make some sense, it’s hard to see were the parties new leader could magic some “Tory-busting cruise missile” from.

More support for the miliband’s bid for power comes thanks to Rachel Sylvester in the Times, who having spoken to a Cabinet minister or two, thinks that one of the brothers is the likely contender for Mandelson’s support and, therefor, the party leadership:

“There are many who hope that the Miliband brothers, having saved the world, will save their party. For years Labour was dominated by the political brothers, Mr Blair and Mr Brown, whose rivalry tore the family apart; now the leadership is hovering between two real brothers who, for the moment at least, remain friends.

It’s no good going for a caretaker candidate, fun though Alan Johnson is. Labour needs a leader who looks ready for the future and really wants the job. The party has to move on to the next generation.”

Sylvester hints that Mandy may well switch his support to Miliband the elder. If that is true, then it is all over for Brown.

Mandelson has always been a shrood operator and it’s no surprise that he is looking around for the next leader to support. One thing that must be on his mind though is timing, for if Mandelson announces that he would support Miliband (or any other Cabinet member) then it’s all over for Brown as PM.

While this would be a spectacular end to Gordon Brown’s premiership the likelihood of it blowing up in public is very slim. As we know from the Blair/Brown tussle of 1994 Mandelson likes to work behind the scenes to build up his candidate and weaken opponents, and I suspect we will see, or not see, the same again.