I recently noted that the NHS budget isn't as safe as the coalition suggests. Since the rate of health-service inflation is higher than in the economy as a whole, the government's pledge to protect NHS spending will be met only if economy-wide inflation measures are used.

Under the coalition's plans, spending will rise by 0.1 per cent a year in real terms, but this increase will be wiped out by the cost of new drugs, medical technology and an ageing population, meaning that the NHS will, in effect, suffer a real-terms cut of 5-6 per cent.

Today comes news from the Royal College of Nursing that 27,000 posts have been earmarked for cuts, more than three times the number identified last April. Dr Peter Carter, chief executive of the RCN, has attacked the "urban myth" that the NHS is being protected, stating: "the evidence we have gathered is quite clear: that is not the case."

He added: "The public should be really concerned about the potential impact to the NHS. I predict waiting will rise. It won't be too long before people start asking what is going on."

The highly political pledge to ring-fence the NHS was originally made as part of David Cameron's attempt to "detoxify" the Conservative brand. But one wonders if the coalition has now raised unrealistic expectations. The public may be prepared to tolerate large cuts in public spending, but they won't happily be deceived.