To ensure prudence remains Gordon Brown's middle name, the IMF suggests that Brown toughen up his fiscal targets. Instead of holding the national debt target at 40% of total output, he might consider lowering it towards the current 31%, locking in some of the gains achieved. Certainly, the IMF does not like the idea - floated in the PRB speech - that additional health spending be paid for by higher taxes. This, it says, would damage the 'neutrality' of Britain's tax system.