The aim is to make surgery safer, and to minimise the risk of errors by introducing a more consistent approach.

The guidance has been drawn up by the National Patient Safety Agency and The Royal College of Surgeons of England.

A review of cases from the Medical Defence Union over 13 years from 1990 found 306 claims resulting from surgery which went wrong.

Mistakes during surgery can have devastating emotional and physical consequences for patients and their families Professor Sir John Lilleyman

Of these, 39% were concerned with operations being carried out on the wrong side.

Half (49%) were concerned with the wrong tooth being removed during dental operations.

One in five occurred in the specialty of orthopaedics and trauma.

And data from a NPSA pilot study involving 28 acute trusts identified 44 incidents in 10 months to June 2002.

The problems are thought to be linked to the fact that until now there has been no national guidance on how to prepare patients for surgery.

This means that staff who move from one trust to another may not be familiar with the local protocol.

The new guidance covers where, how and when the patient should be marked, who should do the marking and the people who should be involved in the process.

Professor Sir John Lilleyman, NPSA medical director, said: "Mistakes during surgery can have devastating emotional and physical consequences for patients and their families.

"For the staff involved too, incidents can be distressing, while members of their clinical teams and the wider organisation can become demoralised and disaffected.

"Implementing these new recommendations will help surgical teams make patient care safer."

Mr Hugh Phillips, president of The Royal College of Surgeons of England, urged all surgical teams to adopt the guidelines.

He said: "The aim of the guidance is to promote best practice to help improve patient safety. "

The guidance has been widely welcomed by the medical profession.

Melanie van Limborgh, of the National Association of Theatre Nurses, said: "Standardising marking and verification procedures for surgical patients will provide reassurance for patients and the public at large.