Labour is increasingly confident that it is not just right in principle to oppose  George Osborne's 1 per cent cap on benefit increases but also right politically. While Osborne, the Conservatives' chief election strategist, believes that the measure will increase support for the Tories among those voters who considered the last government too soft on welfare claimants, Labour argues that he has miscalculated by hitting the very "strivers" he claims to support. Sixty per cent of the real-terms cut to benefits will fall on working households and, according to the Institute for Fiscal Studies, the average one earner couple will be £534 a year worse off by 2015.
Overnight, Labour released some fascinating HMRC data showing how the cuts to tax credits will hit voters in Conservative marginals. In the Tories' 60 most vulnerable seats , there are an average of 15 working families receiving tax credits for every one marginal voter. For instance, in North Warwickshire, the party's most marginal seat (held by 54 votes at the last election), there are 6,800 families receiving working tax credits. In Broxtowe, the 10th most marginal (held by 389 votes), the figure is 5,700, in St Albans, the 40th most marginal (held by 2,243 votes), it is 6,700.
A Labour spokesman said: "Everyone knows the next election will be a living standards election. George Osborne's strivers' tax is going to hit working families in Tory-held seats. He thought he was playing a clever political game, but instead he is likely to find he has cost the seats of dozens of his colleagues."
If this sounds a lot like wishful thinking, the thesis that austerity will cost the Tories votes at the next election remains a plausible one. A frequent complaint heard by Conservative candidates on the doorstep in 2010 was that the party planned to take away their tax credits. Now it has done so, the electoral fallout is hard to predict. But the belief that in-work voters deprived of their benefits will be assuaged by the knowledge that others are suffering more is no more convincing than the belief that they will fall into the arms of Labour.