The Office for National Statistics started a fierce disagreement over output and productivity in the National Health Service yesterday as it launched a consultation into the issue, writes Chris Giles.

The ONS reported that different techniques could show NHS productivity rose by 1.6 per cent a year between 1999 and 2004 or that it fell by 1.5 per cent a year. Official figures show a decline of close to 1 per cent a year.