Politicians seem to fetishise laws that bind their own hands

What is the point of government passing a law to stop it doing something when it can just as easily repeal it? If George Osborne were still to find himself Chancellor after the election I can’t see that we would feel any more bound to abide by a law fixing the rates of income tax, National Insurance and VAT than he would by a pledge to the same effect.

If he ever fancied notching up VAT in a future budget all it would take is a clause in the finance bill excusing himself from such a law. In any case, we haven’t yet seen the text of the tax-fixing bill which David Cameron proposes today. You can bet it will contain a get-out clause, as with Ed’s promise to fix energy prices, saying that it can be overlooked in a state of economic crisis – which, given that the public finances seem to exist in a perpetual state of crisis, just about covers every eventuality.