M&S is selling the "Sleepsafe" pyjamas, below, at 100 stores as part of a trial.

Silver-laced nightwear has been tested in a handful of hospitals, but M&S has become the first retailer in Britain to stock the pyjamas.

They are only available for men at present and come in three colours - teal, navy and burgundy. A spokesman for M&S said: "They are produced using a fabric which has two per cent silver woven into it. Silver is know for its infection fighting properties and has previously been used by the military.

"The fabric that the pyjamas are made of has been clinically proven to reduce the risk of MRSA by killing bacteria that come into contact with the fabric. Clinical trials are currently ongoing and are three quarters of the way through. The interim results were positive."

Katherine Murphy, from the Patients' Association, said: "We welcome the fact these are going on sale, but it shows how desperate the public is."

Dr Mark Enright, a microbiologist at Imperial College London, said that the pyjamas could reduce MRSA colonisation on the skin that could reduce the risk of getting an MRSA wound infection.

However, Tony Kitchen, of MRSA Support, said: "It sounds like a gimmick - it cannot be a super suit and probably doesn't make a jot of difference.