Patients reacted angrily yesterday to the medical profession's decision to allow a surgeon in the Bristol heart babies scandal to resume unsupervised operations.

Janardan Dhasmana was banned from child surgery and unsupervised heart surgery for three years after the scandal at Bristol Royal Infirmary, which left 29 children dead and four brain damaged between 1988 and 1995.

Last year he was given permission to carry out heart surgery as part of his retraining, provided he was supervised and did not operate on children. On Tuesday the General Medical Council ruled he could begin unsupervised heart surgery again after he undertook never to perform heart operations on children.

After the ruling, Steve Parker, of the Bristol Heart Children's Action Group, said the families were "very disappointed" by the decision, which was a "serious worry".

"We don't agree with the overall ruling but it's a bit of a mixed result because effectively it does say that if Mr Dhasmana breaks his undertaking then that would constitute serious professional misconduct," he said.

"It means he cannot work on children ever again, which is what we wanted, but he's free to work on adults unsupervised and that is an issue of patient safety. The GMC has given the doctor the benefit of the doubt and has not put patient safety first," he said.

The deaths of so many children at the Bristol hospital led to a multi-million pound inquiry which recommended more open and accountable behaviour by surgeons.

Mr Dhasmana was found guilty of serious professional misconduct and banned from child operations, though he was not stopped from operating on adults. His colleague James Wisheart and the hospital's chief executive John Roylance were both struck off.

A spokeswoman for the General Medical Council said Mr Dhasmana had not operated on children for more than six years and would in effect be barred from child heart surgery because of the time gap.

The GMC's Professional Conduct Committee said Mr Dhasmana's consultant at Newcastle praised him as "a conscientious and good colleague". Mr Dhasmana's lawyer said the surgeon, now in his 60s, was relieved by the ruling. "Mr Dhasmana wishes to express once again his deepest sympathy for the families who have lost a child," he said.