Were Labour to ban men from voting, it would be re-elected with a majority of 68. That's according to today's Independent/ComRes poll, which puts support for Labour among women voters at 36 per cent, a 4-point lead over the Conservatives. By contrast, the Tories are favoured by 43 per cent of men, a 16-point lead over Labour.

Up until 1997, the Conservatives laid claim to being the natural party of women, with the gender gap working in their favour. If women had never been granted the vote the Tories would have been out of office for the entire postwar period. But that changed with the emergence of Tony Blair, and Labour has led among women voters in every election since.

Cameron has worked hard to win back female voters by promising to ring-fence health spending and to make education a priority (women are greater users of public services than men), but Labour has maintained the 4-point lead it enjoyed among female voters at the 2005 election.

One reason women drifted towards the centre left was that it was Labour that pushed for and introduced extended maternity leave, flexible working and programmes such as Sure Start. It may be that Cameron needs to adopt a greater focus on such issues.

In any case, as fear of a hung parliament grows in Tory circles, it is clear that it is female voters who will once again decide the outcome of the election.

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