The latest poll (by YouGov for The Sun) has the Conservatives just 6 points ahead of Labour, with 38 percent compared with 32 percent. The Lib Dems are on 17 percent. Assuming a uniform national swing, that would leave the Tories 34 seats short of a majority.

The first thing to say about this is that we're almost certainly not going to see a uniform national swing at the election. The Tories have have been focusing their resources on the marginal seats that are going to decide the election, and polling suggests that they are doing better in these seats than they are nationally. That means they are likely to win more seats than pundits are currently predicting.

Nevertheless, there remains an interesting question here – why aren't the Tories doing better? The economy has gone down the pan. Gordon Brown couldn't be more unpopular. And Labour has been in for 13 years, meaning the political pendulum is almost certainly swinging against them (all governments run out of steam in the end). On this basis, the Tories should be polling comfortably above 40 percent, and maybe even pushing 50 percent.

The reason they're not, in my opinion, is because it remains more-or-less impossible to answer the question, 'what are the Tories going to do for me?' I follow politics closely, and I've really got no idea. So why should they expect the man on the Clapham Omnibus to bother voting for them?

If he wants to win big, David Cameron needs to find a more convincing 'retail pitch', and fast. I know Britain's precarious fiscal position leaves little room for manoeuvre, but at the very least he should promise that there will be no tax rises, no new taxes, and that any tax hikes already scheduled for 2010 and 2011 will be cancelled.

I also think that there is a rich vein of public sentiment to be exploited by railing against all the incremental infringements of our liberty that we have suffered over the last decade – promising to get rid of all the bureaucratic little Hitlers that make British lives a misery would surely be a vote winner. In 1951, Winston Churchill campaigned under the slogan "set the people free". If the Conservatives want to reverse their decline in the polls, they desperately need to capture that same sentiment.