John Rentoul: Politics reduced to a walk in the park

The election may be a long way off but the parties are laying the groundwork for a hung Parliament that looks increasingly likely

They do their homework, these Conservatives. George Osborne, the shadow Chancellor, surprised lunch guests recently by retelling the story with which Professor Peter Hennessy opens his magisterial work, The Prime Minister: The Office and Its Holders Since 1945.

It concerns a walk in St James's Park taken by Sir Martin Charteris, the Queen's private secretary, and Sir John Hunt, the Cabinet Secretary. They talked about Ted Heath's wish to carry on as Prime Minister after his parliamentary majority was swept away in the February 1974 election. Heath felt that he should be given a few weeks to see whether he could piece together a new majority with the help of the Liberals and minor parties. The two men in the park felt not, and agreed that the Queen should be advised to invite Harold Wilson, as leader of the largest party in the House of Commons, to form a government. "I remember 1974 ," said Osborne. Surely not, protested a fellow diner. "I was two at the time," said Osborne. "I've got a good memory."

He certainly has a good understanding of contemporary history, and his interest in that period is intriguing. Last week the new leader of the Liberal Democrats, Nick Clegg, seemed to say something significant about the prospect of working with the Tories if there were a hung parliament after the next election. In fact, I am told that Clegg had no idea that the Financial Times would put the headline "Lib Dems could back Conservatives" on his interview, which was mostly about economic policy.

If we look closely at his words, he did not say anything that he has not said before. The Liberal Democrats are "equidistant" between the two larger parties, he said. Asked whether he might support a Tory Queen's Speech, he said: "I don't care who produces a more liberal document for government. If it is more liberal, then of course I would be interested to look at it."

Nevertheless, the FT is to be congratulated on what John Birt at the BBC called a scoop of interpretation. What is important about Clegg is that he does not take the same view as Sir Menzies Campbell, his mentor and predecessor. Sir Menzies was not equidistant from anyone. He is an anti-Conservative who hoped to join Tony Blair's Cabinet in 1997. Even Charles Kennedy, who was hostile to the idea of working closely with Labour, was still more hostile to the Tories. "Europe," he said to me once, very quickly, when I asked him why he shouldn't support a minority government led by David Cameron. Clegg, though, is different.

So there is no sudden sidling-up, but the replacement of Sir Menzies by Clegg was an important shift in the basic alignment of British politics. The Liberal Democrat membership remains deeply anti-Tory, but its leadership is now open to the prospect of working with either of the larger parties, issue by issue. That in turn draws attention to another tectonic shift that took place two years ago.

When Cameron became Tory leader, one of his innovations was to "love-bomb" the Liberal Democrats. This is a public version of the secret talks between Blair and Ashdown before the 1997 election: an attempt to scoop up Lib Dem votes by adopting Lib Dem policies and being nice to leading Lib Dems.

Although the mask sometimes slips in private, it is difficult to get Cameron's inner circle to be rude about the Lib Dems. I am told that when one of the circle was asked if he were worried about Clegg competing in the young, posh and moderate market, he said no, not at all. No surprise there, although his reasons were unexpected. It helps to widen that space in politics and to emphasise the contrast with Gordon Brown, he said, and it allows the Tories to concentrate on "flags and fireplaces" – in other words, on presenting Cameron with the trappings of a potential prime minister.

It is part of a wider big-tent strategy, an attempt to associate the Tory brand with influential people who signify success. Since Brown became Prime Minister, he has been competing fiercely with the Tories for celebrity endorsements, even persuading a handful to serve as ministers.

Hence the Conservative high command's delight at last week's Black and White Party, a fundraising event formerly known as the Black and White Ball – a change of name that is itself a socio-political marker. For who should show up but two of Brown's top catches? My spies at the Battersea venue report sightings of Mervyn Davies, chairman of Standard Chartered Bank, who is also chairman of the Prime Minister's "Business Council"; and of Sir James Sassoon, the former managing director of UBS Warburg, now working for the Treasury as president of Brown's Financial Action Task Force.

This is High Politics with a capital P. The election is a long way off – all the Shadow Cabinet members to whom I speak expect it in 2010. But they have to work on the default assumption that a hung parliament is likely. Then, if Labour is the largest party, Brown will be in the curious position of having been rejected by the voters but – on the 1974 principle – entitled to have first go at forming a new government. The Liberal Democrats would be reluctant to be seen as propping him up. Equally, if the Tories have most seats, Clegg might support them on green issues and civil liberties but his party would not let him enter into any formal pact.

In any case, neither Labour nor the Tories are likely to offer the Lib Dems the starting price for any deal, namely electoral reform. Hardly noticed two weeks ago was the publication of a Government review of voting systems in the UK, which concluded that the present system for the House of Commons should not change. It left open the possibility of looking at the issue again when House of Lords reform is completed. That is, on the 12th of Never. And Cameron and Osborne remain emphatically opposed to change.

Either way, therefore, a minority government seems more likely than a formal coalition. It would have to take its business through the Commons day by day and issue by issue, as Wilson did in 1974. One Shadow Cabinet minister said to me last week that Alex Salmond in Scotland had shown how a minority administration could be surprisingly successful and popular.

But who gets to form a government if the election is inconclusive is an imprecise science. It doesn't go to a Supreme Court that can give the election by five votes to four to George Bush. It might go to a Walk in the Park. Cameron and Osborne know that the mood of the nation, as divined by the great and the good, could be decisive. Hence their big tent approach.

"If the electorate should ever again wobble inconclusively," wrote Professor Hennessy, "you will find me on the following Saturday forsaking my customary weekend pleasures at the South Chingford Sainsbury's for a bench in St James's Park... For who could resist witnessing the British constitution in motion against such a perfect backdrop?"