The Bristol inquiry has announced that its final report will not be completed until the end of March, when it will be sent to health secretary Alan Milburn.

The delay - caused by the chief medical officer's request last year that the inquiry focus its attention on the removal and retention of organs - has sparked speculation that the report will not be made public until the summer.

Lawyer Mervyn Fudge, representing 30 of the Bristol families, said his clients were disappointed that the report's publication had been delayed. He said he suspected the report would be withheld until after the election: 'This is not going to be a vote winner - people have forgotten that what happened, happened during the Conservatives' reign.'

News of the delay coincided with a press report at the weekend, which claimed the inquiry found that 'institutional arrogance' in the NHS was to blame for the heart surgery scandal.

According to The Sunday Times, the report calls for the divide between doctors and managers to be addressed and criticises the 'macho medical culture' and 'unhelpful internal politics' at Bristol Royal Infirmary. It is also said to find that the monitoring and regulation of doctors and managers was inadequate.

But the inquiry has denied the story was based on its final report, and said that the 'vast majority' of the material was drawn from reports of seminars published last year on its website.

A BRI spokesperson said the trust would not respond to 'speculation or supposed leaks'.