Confronted with the Tories' stubbornly high poll lead, Labour comforts itself with the thought that economic recovery now seems to be under way. Figures released later this month are expected to show that after a record six quarters of recession, the economy finally began to grow in the last three months of 2009.
Labour optimists believe their party stands to gain from this development. As UK plc gets back on its feet, they expect voters to recognise that Gordon Brown - though he may not have "saved the world" - did stop the recession from turning into a depression. And they anticipate increasing wariness of George Osborne's pledge to cut spending immediately if the Tories are elected.
But history suggests the government may not be this fortunate. John Major suffered a landslide defeat in 1997 even though, come polling day, the economy had been growing for four years. Instead of crediting Major with economic recovery, voters remembered him as the man who had presided over the UK's humiliating withdrawal from the Exchange Rate Mechanism in 1992. Similarly, they are likely to remember Brown as the man who boasted that he had "abolished boom and bust", before leading the UK into the deepest recession since the Second World War.
There are some reasons for Labour to be cheerful. This time last year, economists were predicting that unemployment would hit three million by early 2010 and that house prices would fall by at least 20 per cent. In fact, unemployment has remained under 2.5 million and the property market has now grown for seven consecutive months. House prices, in particular, tend to have a greater effect on government support than GDP (see graph).
Ministers can persuasively argue that the UK would be in a worse position had the Tories been in power. Some economists estimate that under a low-spending Conservative government, nearly half a million more people would have lost their jobs. But the difficulty remains that while voters may blame governments for economic failure, they rarely credit them for recovery. Given the increasing presidentialisation of British politics, any late Labour poll boost is more likely to be down to the televised leaders' debates than economic recovery.
The wedding party
Lately, the polls have mostly made good reading for the Conservatives. But Tory strategists have been troubled by an apparent fall in the party's female support. The latest ComRes/Independent on Sunday poll put the Tories 20 per cent ahead among men but only 6 per cent ahead among women.
Women's votes were crucial to Labour's success at the last election - 38 per cent of women voted for the party, compared with 34 per cent of men. Without female voters, Labour's majority in 2005 would have been 23 seats, rather than the 66 it actually won.
A possible explanation for the disparity between male and female support for the Tories is their policy on marriage. In December, a ComRes poll found that only 39 per cent of women agree with David Cameron's plan to support marriage through the tax system; 52 per cent actively oppose it. Ask a mixture of men and women, and opinion is split 46-46. But a significant number of women have told pollsters that they feel patronised and excluded by Cameron's pro-marriage stance.
In its attempt to deny Cameron a majority at the election, Labour would do well to make marriage a key point of difference between itself and the Tories.