The Taxpayers' Alliance, an estimable body which seeks out waste and tries to prevent it, is vexed by Whitehall's taxi bill. It's £8 million a year, apparently. Mathew Elliot, the alliance's chief executive, calls this "excessive".

Now £8 million is a fairly big number, but it's important not to be impressed by bigness. Whitehall is also big - very big indeed. There are 19,000 members of the First Division Association, the union which represents the mandarins.

If we assume that only these top people are taking taxis - a very generous assumption indeed - the annual bill per mandarin is £444, or £8.50 a week. That's one not very long taxi ride, at today's London prices.

A war on waste is doubtless desirable. So is a sense of proportion.