For the last few months it has been hard to get through a newspaper without some article pontificating about David Cameron’s allure to swing voters. His boyish, Blairish, pram-pushing, nappy-changing, mug-washing, blogtastic friendliness.

What those articles haven’t mentioned is that out in the real world and away from the media village, swing voters are not actually warming to David Cameron. Contrary to the media narrative, focus groups I have conducted have increasingly shown ambivalence, and often hostility, to a man who, as one participant put it, is beginning to come across as all mouth and no trousers.

So it came as no surprise to us when an opinion poll we conducted alongside Populus for our new thinktank – the Opinion Leader Forum – found that it is Brown, not Cameron who swing voters prefer. When asked who they would prefer to be the next prime minister, 24 per cent of swing voters picked David Cameron, while 51 per cent picked Gordon Brown.

Looking behind these figures, it seems that one reason for Brown’s lead is that that swing voters are more likely to trust him to set the country in a better direction as prime minister. While 41 per cent of swing voters agreed that Cameron would set the country in a better direction, 48 per cent agree that Brown would. And, because more people disagree that Cameron would than Brown would, Brown enjoys a 12 per cent lead in the net scores (the total proportion who agree minus the proportion who disagree).

Swing voters also rate Brown’s personality more highly than Cameron’s on several key measures. Brown has a 27 per cent lead on the net proportion of swing voters who see him as ‘strong’, while Cameron is 22 per cent behind on having ‘substance’. The only crumb of comfort for Cameron is his modest eight per cent lead on listening to the public – a lead dwarfed by Brown’s astonishing 92 per cent lead on being experienced.

Of course it’s still relatively early days for Cameron and there is plenty of work for Labour to do before the next election. But these numbers show that it is Cameron, not Brown, with a mountain to climb among swing voters.

It is worth briefly thinking about why these swing voters matter. Our poll picked out two groups of swing voters: those currently intending to vote Labour but open to voting for another party, and the much larger group who are currently not voting Labour but are open to doing so. Ultimately, it is these people in marginal seats who will decide the next election. If Labour holds on to the voters currently planning to vote Labour, then on current horse-race standings, the Tories will need to reach something like 44 per cent to win an outright victory – a number they haven’t reached since the 1970s. If Labour makes inroads into the group of swing voters that are open to voting for them but not currently doing so, the Tory task becomes just about impossible.

In light of this poll, there are two interesting things to watch out for. First, these numbers should lead to a change in the media’s assumptions about how Cameron and Brown will shape up against each other. With Brown clearly leading among swing voters, and with the latest Mori poll showing Labour to have a two point lead, it will be interesting to see if Cameron’s media bubble bursts.

Second, it will be interesting to watch Cameron’s strategy. There are of course two ways to secure votes. You can attempt to appeal to the swing voters – as Cameron has so far – or you can focus on mobilising people who would vote for you if they were to vote, but are not currently likely to make it to the ballot box. This was the approach the Tories focused on unsuccessfully in 2001 and 2005, and they are right to have knocked this strategy on its head this time. But if Cameron’s efforts to seize the middle ground are seen to be failing, the pressure from the right of his party to jag back their way is likely to rise. This is exactly what happened to Michael Howard, IDS and William Hague, who all started out by tacking to the centre before being dragged back to the right when they lost the ability to control the right of the party. Will history repeat itself?