Prof Stephen Hawking has attacked Health Secretary Jeremy Hunt, accusing him of making “silly” claims in a row over NHS privatisation.

Last weekend the physicist and lifelong Labour supporter claimed the health service was moving towards a “US-style insurance system” under the Tories.

Mr Hunt hit back, writing in today's Telegraph that while Prof Hawking was a “personal hero” he had made claims which had no evidence to back them up.

The Health Secretary said the number of people insuring themselves privately had fallen by 9.4 per cent since Labour’s last full year in office, while NHS spending on the private sector had risen by just 0.1 per cent in the last year. And he said the government had no intention of moving towards an insurance-based system, which was often the least effective way to contain costs amid rising demand.

In today’s newspaper, Prof Hawking accuses the Health Secretary of using “silly” figures to make his case.

He writes: “Jeremy Hunt says the NHS can’t be moving towards a US-style system because the number of people privately insured is lower than in 2009. But this is due to the financial crash and is not a reliable predictor of the future.”