The UK's system of private medical and life insurance will have to be shut down by the middle of the century because of advances in genetics, according to the head of Cancer Research UK.

Sir Paul Nurse, a Nobel prize winning scientist, uses an interview in today's Guardian to claim that private insurers would not be able to deal with the predictive power of genetics and a larger version of the NHS would have to be considered.

He argues that the government will one day use large scale screening to test for individuals' susceptibility to disease such as cancer.

Sir Paul also criticises the government for not dealing with the dangers of tobacco.

"When you see how much fuss is made about cannabis and you see the number of deaths caused by tobacco, you just have to throw up your hands in disbelief," he said.