Alex Salmond is a difficult neighbour. The leader of the independence-seeking Scottish National party and first minister of Scotland announced plans this week to abolish the council tax and replace it with a local income tax. By highlighting the awful state of the UK's local government system, he has invited a fight with politicians in London and made tensions in the Union impossible to paper over.

Council tax is a locally set levy linked to property values. Since the government has no mechanism for reassessing house prices, however, it relies on old information - most taxpayers are charged according to what the value of their house was 17 years ago. It is regressive and, thanks to the automation of the UK tax system, it is the only tax that routinely requires most taxpayers to fill in forms and write out cheques. Even by the standards of taxes, council tax is unpopular.