John Rentoul: The special relationship

The return of Lord Mandelson of High Mischief sets up a taut psychological drama for 2009. Talk about flaws. It is as if the scriptwriters of Lost have turned their hands to the soap opera that is British politics, and decided that they needed a twist so outlandish that explaining it may require recourse to the supernatural. It is a twist that creates a series of tense relationships and puzzles for the writers to resolve as the plot unfolds over the coming year.

So far, we have merely had a teaser. We should, therefore, open our preview of politics in 2009 with "Previously on Cabinet Capers...". The immediate reaction to Peter Mandelson's return was one of shock and revulsion. Libby Purves wrote: "Hideous, hideous mistake. Akin to... getting back together with a sixth-form boyfriend on Friends Reunited." The Daily Mail gave him a front-page welcome: "Arise, Lord Sleaze". But almost the next day, his return was hailed as a remarkable appointment by a Prime Minister who turned out to be able not just to save the world but to forgive his greatest enemy.

It was hailed most effusively in these terms, it must be said, by Mandelson himself. A few days ago, he recalled the halcyon times of only a few weeks earlier. "Tony Blair used to say his mission would be complete when the Labour Party learned to love Peter," he said, talking of himself in the third person. "In my first few weeks back in the Government, there was a risk of that coming true."

The great reconciliation acted as a metaphor for the Labour Party's rediscovered sense of unity, even though that togetherness was in fact engendered by Gordon Brown's recovery in the opinion polls as a result of the bottom dropping out of the markets. So, for a few weeks, before he ran into a bit of opposition to Post Office privatisation, he basked happily in the warm glow of Labourites relieved not to be talking about getting rid of Gordon any more. And he luxuriated equally happily in the attentiveness of the media, most of whose representatives were delighted to have him back because it gave them something interesting and personality-based to write about.

So what surprises do the scriptwriters have in store over the next 12 months? One of the few certainties, on a par with the knowledge that it will be International Year of Natural Fibres all year, is that Mandelson will be the character around whom the drama will revolve. David Cameron has been a leading player for so long – three years – that we have almost lost interest. Boredom Brown was never that interesting on his own, anyway – we only saw in him all manner of brooding complexes because of his peculiar relationship with Tony. Brown and Cameron have no relationship to speak of, apart from a mutual contempt so deep that it is monotonous. But Brown and Mandelson, now that is a story.

We know some of how the year will start. There will be crises and brinkmanship in the bailing out of Jaguar Land-Rover and other "strategic" industries. Mandelson will be there. There will be a decision on a third runway at Heathrow, delayed from earlier this month but promised for January. Mandelson will be there. There will be speculation about the date of the next election, inflamed rather than suppressed by the Prime Minister's game of ruling out months one or two at a time. Mandelson will be there.

Indeed, one of the other predictions that can be made with some certainty is that a significant volume of political reporting and commentary during 2009 will be devoted to the subject of election timing. The council and European elections on 4 June will be kept open as a general election date for as long as possible. If Brown decides against it – and he will have to make that decision early in the new year, because no form of words can hold the option open for long, given the experience of September/October 2007 – then the media herd thunders straight on to an autumn election, depending on the opinion polls. That will go on all year, or at least until the issue is resolved one way (a dash to the polls) or the other (a definite postponement until 2010).

Of course, the great big plotline that the scriptwriters are keeping under lock and key in a secure vault is the path of the recession. It could be "deeper than any that we have known", according to Tessa Jowell, the Olympics minister, or it could be "in the shape of the Nike 'swoosh'", in the words of John Healey, the Local Government minister. Presumably, that kind of recession would be short and sharp, with the recovery starting any moment now, although Healey did not say how far down the first part of the tick – sorry, swoosh – will go.

The one thing that is most unlikely to happen, just because he predicted that it would, is that the recovery will begin in the third quarter of 2009, which is what Alistair Darling, the Chancellor, said in his mini-Budget in November.

Not that it is obvious what the consequences of different kinds of downturn will be. But the Secretary of State for Business, Enterprise and Regulatory Reform will be in the thick of it. How could he not be? The most striking device of the scriptwriters was to put Mandelson on 33 of the 39 cabinet committees that are, in Professor Peter Hennessy's great analogy, the "hidden wiring" of British government. Indeed one of the committees that he is not on, Civil Contingencies, does not exist until there is a contingency for it to deal with. It has a chairman, the Home Secretary, and then other ministers are "invited to attend depending on the contingency". And another committee, Legislation, has his junior minister, Shriti Vadera, as a member. So you could say he is represented on 34 out of 38. The only Mandelson-free committees are Nuclear Security, Overseas and Defence, Tackling Extremism, and Security and Intelligence. Which means that, of the predictable events of the Westminster calendar in 2009, only the pull-out from Iraq will be nothing to do with him.

However, while Mandelson is largely devoted to the occupation of ensuring Brown's re-election, other subplots will develop away from the main action. Two of the most intriguing are the covert Labour leadership campaign and the dancing around Nick Clegg, as the possible kingmaker of a hung parliament.

The emerging rivalry between Ed Balls, the Secretary of State for Children, Schools and Families, and James Purnell at Work and Pensions, is hardening into the assumption that they will confront each other when Brown stands down, either after election defeat or soon after an inconclusive result.

At some point during the year, it is likely that the opinion polls will be less favourable to Brown than they are now. Then we might see a resumption of speculation about replacing Brown in order to save Labour from humiliating defeat, possibly with Purnell cast in the role played by David Miliband in 2008. Meanwhile, the possibility of a hung parliament within the next 18 months is focusing Labour and Tory minds on the virtues of being nice to Liberal Democrats. Once again, Mandelson, a long-standing dabbler in inter-party dialogue, will be at the heart of the action.

We left the last episode of Cabinet Capers on a cliffhanger at the end of 2008, with Mandelson poised between hero and villain. Over Post Office privatisation, unfinished business from his previous spell at his department, cut short 10 years earlier, he was excoriated by Labour backbenchers for "returning to his own vomit" (as Austin Mitchell, showing a flash of the old invective that made him one of the most quotable MPs in Neil Kinnock's day, put it). Yet at the same time he was praised to the skies as the heir to Herbert Morrison (oh, he is: grandson on his mother's side) by Labour columnists for trying to bounce the Treasury into tipping further billions of taxpayer's cash into Britain's car makers.

The politics of 2009 will be shaped in no small measure by Mandelson's success in that balancing act.

Six to watch: Political stars most likely to shine

James Purnell Secretary of State for Work and Pensions. One of the less well known members of the Cabinet, he seems too young, too inexperienced, and has not yet developed the natural authority of a leader. Yet he has many of the qualities required to stake a claim to the succession: a reputation with the Civil Service as an effective minister and a creative political instinct that sells New Labour policies as the fulfilment of Old Labour values.

Tom Watson Most senior of the rebels who curtailed Blair's premiership and resigned as a defence minister in the coup of September 2006. Currently Digital Engagement minister based at the Cabinet Office. Now this has become a Prime Minister's Department in all but name, he is at the centre of things, with a desk in Gordon Brown's open-plan command centre at No 12. He is likely to be at the centre of any manoeuvring if Brown's leadership comes under threat.

Rushanara Ali Look out for the new Labour MP for Bethnal Green and Bow, almost certain to replace George Galloway at the general election now the Respect coalition has caved in. Spotted by Michael Young – credited with writing the 1945 manifesto – when she was still at Oxford, she went on to work for the Young Foundation, named for him after his death in 2002. There she works with director Geoff Mulgan, an adviser to Brown and the first director of Blair's Strategy Unit.

Jeremy Hunt Told Islington Tories this: "God summoned Bush, Putin and Lord Mandelson. He said mankind was so bad He would destroy the world. Putin told the Duma he had two bits of bad news. God existed; and the world would end. Bush told Congress he had good and bad news. God existed; and the world would end. Mandelson said he had two bits of good news. He really was one of the planet's three most important people; and David Miliband would never lead Labour."

Justine Greening Likely to make it into the Shadow Cabinet in Cameron's next reshuffle, her rapid rise – her Putney seat was one of the first Tory gains from Labour in 2005 – has put older male Tory noses out of joint. Presumably because she is a woman, unlike Michael Gove and Jeremy Hunt, who have also been in the Commons for three-and-a-half years. Hasn't their wit or Y-chromosomes, but comes over well on TV. Fits the youthful profile of the new Tory party.

Danny Alexander The new MP for Inverness who is "chief of staff" to Nick Clegg, a position that makes him a key player in the negotiations that will gain in intensity next year between the parties about what might happen in a hung parliament. It also a position that puts him in the seat next to Clegg when the Liberal Democrat leader is expounding on the uselessness of his senior colleagues on the flight from Gatwick to Inverness, with a 'Sunday Mirror' reporter in the seat next to him.