Patients in nearly half of all emergency night-time operations are anaesthetised by trainees, while one in five procedures are performed by junior surgeons, a report says today.

The night-time figures are an improvement on five years ago but are "still cause for concern", according to the National Confidential Enquiry into Perioperative Deaths, an independent body funded by the National Institute for Clinical Excellence.

They studied information on surgery collected from 557 hospitals over two months last year and concluded there was still a need for more out-of-hours supervision between 6pm and 8am.

The one in five operations performed by inexperienced surgeons has improved, says the report, Who Operates When, from 65% in 1996.

Health minister Lord Warner said the report showed that progress was being made in the quality and safety of operations.

He said: "Of course it will take time to train all the extra staff we need, but record investment means that nurse, doctor and bed numbers are all rising."