The Tories' new ad campaign (see above) is the party's most shameless attempt yet to turn "the strivers" against "the scroungers". The online ad will run in the 60 Conservative marginals where, as Labour has highlighted, the number of families receiving working tax credits is greater than the MP's majority. Since tax credits, like other working-age benefits, will only be increased by 1 per cent for the next three years (below the rate of inflation), Labour has accused the government of imposing a "strivers' tax". Sixty per cent of the real-terms cut to benefits will fall on working households and, according to the Institute for Fiscal Studies (IFS), the average one earner couple will be £534 a year worse off by 2015.

The Conservatives' response is the demagogic ad above, which asks, "Who do you think this government should be giving more support to? Hard-working families or people who won't work?", and includes an image of a "scrounger" with his feet up at home. The "support" mentioned by the ad is a reference to the planned increase in the personal allowance, which will rise by £1,335 to £9,440 from next April, benefiting basic rate taxpayers by up to £267.

But there are two reasons why the ad might prove less successful than the Tories hope. The first is that, as the IFS has confirmed, the average family will lose more from the cuts to tax credits and other benefits than it gains from the increase in the personal allowance. The second is that not all voters will accept the caricature of the unemployed presented by the ad. The majority of those without a job are desperately trying to find work (with little support from the government) and, in most cases, will have been employed and paid taxes for years before the recession. The number who choose benefits as a lifestyle is far smaller than ministers imagine.

For these reasons, among others, polls show that fewer voters than expected support Osborne's benefit cuts. Most notably, a MORI poll published on Thursday found that 69 per cent believe benefits should rise in line with inflation or more.