Gordon Brown is nothing if not predictable. It has been obvious for some time that the 2007 comprehensive spending review will face tough choices on the public finances. So in a little-noticed passage in this year's Budget speech, the chancellor called for "the fullest public debate" on priorities and plans for the next spending round. He hoped it could "build a national consensus around a rising share of investment in education". In other words, he wants the option of raising taxes again.

We have been here before. In 2001, Mr Brown's pre-Budget report called for "a new consensus" on raising "investment" in the National Health Service. A few months later, Sir Derek Wanless reported to the chancellor that NHS spending needed to rise significantly if Britain was to spend the European average on healthcare. Up went National Insurance contributions for employers and employees in the 2002 Budget, boosting the tax take back to levels last seen in the 1980s.