At last it can be officially confirmed: Gordon Brown does listen to Arctic Monkeys. How else can we explain his adoption of their album title – Whatever People Say I Am, That’s What I’m Not – as his main political strategy?

Look at the prime-minister-to-be’s words and actions over the past month, and it is clear that he is on a mission to overturn people’s negative perceptions of him. Too Scottish? He blurs his burr. Too serious? He tries to smile. Anti-reform? He praises city academies and hospital autonomy. Too factional? He invites Jeremy Heywood, Tony Blair’s former principal private secretary, to join him in No 10. Too tribal? He coopts some Liberal Democrats into his government.

Or at least he tries. But, after sleeping on the idea, Sir Menzies Campbell rebuffed him. To most Lib Dems, the offer was such an obvious no-no that they are surprised their leader went home to think about it, rather than declining on the spot.

Lib Dem activists are allergic to deals with other parties, and they are particularly suspicious of Sir Menzies, an old Fife friend of Mr Brown’s. There was talk in 1997 of him entering the Cabinet with Paddy Ashdown (as he then was) and members have always feared that he would pollute the party’s purity for the sake of personal power.

But wiser minds than theirs, MPs who would not object to a coalition after the next election, were equally dubious. They only have to look at the electoral arithmetic. In three-quarters of Lib Dem seats, the Tories are in second place and the sitting MPs are there thanks to the support of former Tory voters. If Lib Dems were to join the Labour Government, it would be much easier for the local Tories to entice those voters back. “A vote for the Lib Dems is a vote for Labour” would be all over their election leaflets.

Had the Lib Dems agreed to field Greg Dyke as a joint candidate with the Tories in the London mayor elections – the deal that fell through in April – then accepting a few ministerial posts from Labour might have been easier. They could still have presented themselves as equidistant and ecumenical; happy to deal with either party when appropriate. Now, though, we are unlikely to see any cross-party co-operation except on non-partisan issues such as constitutional reform.

Yet there were other problems too with the Brown overture. What would the Lib Dems have got out of it? A little credibility, perhaps, in having peers of sufficient calibre to be sought out by another party. But Mr Brown does not seem to have been willing to make any policy concessions in order to woo these potential ministers. Normally, when parties agree to share power, they both offer compromises. Here, the Lib Dems were offered a tiny nugget of power, but only on Labour’s terms. As one senior Lib Dem says: “It’s a highly controlled way of pretending that you’re letting go control.”

And how would collective responsibility have been addressed? Granted, Northern Ireland policy is pretty non-partisan, but what would Lord Ashdown have said, when appearing on Question Time, about other areas of government? As a Cabinet minister, he would be expected to support every Labour policy. On Europe, anti-terrorist measures, ID cards and many other issues, that would have been impossible.

That this was not properly thought through inclines me to believe that Mr Brown’s approach was never really serious. He knew that he would look good whether Sir Menzies and Lord Ashdown said yes or no. Like Nicolas Sarkozy, he would be reaching magnanimously across the political divide. He would confound his critics by appearing open-minded and outward-looking. To those middle England voters who are unaware that the Lib Dems have moved to the left, he would look as if he were joining forces with a moderate, centrist party. To the more politically aware Guardian and New Statesman readers who have forsaken Labour for the Lib Dems, he would be sending a signal that Labour was back on their side. And, by using a fresh, new approach to Cabinet-making, he would be able to present himself as a real change from the Blair regime.

What reinforces my suspicion that this was a slightly cynical ploy is that Mr Brown went ahead with his meeting with Lord Ashdown even after Sir Menzies had stated that no Lib Dem would join the Government. That was surely mischief-making. If the next Prime Minister could have prised Lord Ashdown away from the leadership, it would have made Sir Menzies look weaker still and would have caused uproar within the Liberal Democrat party. To poach talent from your rival party and destabilise it at the same time is a pretty good political result.

The Lib Dem leader has just about extricated himself from this – thanks mainly to Lord Ashdown’s disciplined rebuff – but not without injury. He has now been embarrassed twice, by two different parties: the Greg Dyke negotiation was also leaked at a damaging time, and not by him. As one of his colleagues puts it: “Poor Ming has been made to look like a pawn in a manoeuvre by other parties. This has been a real setback for anyone who wants to take diversity and pluralism in politics seriously.”

Mr Brown, meanwhile, can bask in his new, open, tolerant image, while avoiding having to deal with the bad feelings in his own party that the import of Lib Dem ministers would have caused.

And even if they have turned down his offer, he can still make some counterintuitive appointments within his own party. Expect Charles Clarke to be back in the Cabinet next Thursday. Expect the über-Blairite John Hutton to stay, possibly in a beefed-up job. Expect promotions for younger Blairites such as James Purnell, Liam Byrne and Andy Burnham.

Mr Brown could even shock us all by looking far further afield. Lord Coe, the former Tory MP, as Minister for the Olympics? At this rate, anything’s possible.

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