It looks like desperation. Alistair Darling on Tuesday announced he was putting up personal tax allowances to help those on low incomes hit by the abolition of the 10p tax band. But this was not Gordon Brown’s government making tax policy with an eye to the long-term health of the public finances and a coherent fiscal philosophy. Instead, the chancellor set out a measure more important than any contained in this year’s Budget, in a last-ditch effort to avert a backbench rebellion over the finance bill and avoid humiliation in the Crewe and Nantwich by-election next week.

In policy terms, the plan to put up personal allowances makes sense. Allowances are the best way to direct help towards the worst-off. The £600 increase should mean that four in five households hurt by the abolition of the 10p rate will be compensated in full: the remaining one-fifth will see at least half their loss made up. Meanwhile, the lowering of the threshold at which the higher rate of 40 per cent kicks in means that those on higher incomes are unaffected.