The method was pioneered in the US five years ago, but until now doctors have been unwilling to introduce it here until its effectiveness was proven.

The technique uses argon gas frozen to -140 degrees centigrade, which is injected under the skin to form an "ice ball" around the prostate gland, which is about the size of a walnut and normally produces secretions which nourish sperm.

This rapid freezing kills the tumour cells, although the process is repeated twice to be sure.

It is hoped that the operation will have a success rate of 78%.

Americans training British surgeons

The operation, on an 81-year-old patient, is being performed at the Royal Surrey County Hospital in Guildford, with a team of American surgeons visiting the UK specifically to train British doctors in the technique.

Freezing gas is delivered precisely to the prostate gland

Prostate cancer kills 11,000 men in Britain every year, and traditional methods of treating the disease involve radiotherapy or surgical removal of the prostate gland.

However, both methods can leave men suffering severe side effects, with surgery liable to leave a man incontinent and not guaranteed to remove all the cancer.

Impotence can result from surgery

Surgery for prostate tumours can also render a man impotent. The new freezing method can also affect the nerves which control sexual function, but the difference is that the frozen nerves usually recover within a year.

The key to successful freezing is accurate deployment of the probes which release the super-cold argon gas.

Freezing was first attempted back in the 1960s in Britain, but accurate scanning was one of the obstacles that stopped the method succeeding until now.

The latest hi-tech equipment uses ultrasound to precisely locate the tumour.

Roger Frais, from Cariad Technologies, which is providing the frozen gas equipment, said: "Technology has got to the level where it is possible to freeze the prostate at very low temperatures without affecting any of the surrounding tissue.

"This is really a launch pad for the procedure in the UK."