Leading scientists are calling for changes to the new human tissues bill, which outlaws research using any human tissue, including urine and blood samples, without explicit prior consent.
The bill, which reached committee stage this week, is intended to toughen regulations following organ-removal scandals at Alder Hey Hospital in Liverpool and the Bristol Royal Infirmary.
Both the Wellcome Trust and the Medical Research Council are calling for urgent changes to the "confusing" and "unworkable" wording of the bill, which they fear could stifle vital research in future.
Mark Walport, director of the Wellcome Trust, said: "If this bill were effective now, it might not be possible to carry out research that led to the discovery of genes responsible for the most common inherited form of breast cancer. Indeed it might even be a criminal offence."
Scientists are angry the bill, which suggests a potential three-year jail sentence for medics who fail to gain proper consent for their research, appears to start from a position of mistrust of the medical profession.
David Gordon, dean of the faculty of medicine at the University of Manchester, said: "It reads as though medical researchers are always going to try to do something evil. It might be better to start from an assumption that they are trying to do good."
While the Alder Hey and Bristol cases both involved the removal of organs from dead children, the bill introduces legislation for tissues removed from living patients during surgery or routine hospital procedures, as well as for post-mortem material.
Its definition of human tissue, based on the presence of human cells, means it covers not only the 3 million solid tissue specimens taken in the National Health Service each year, but also blood samples, urine, faeces and sputum.
Many researchers believe such blanket regulation is excessive.
Professor Gordon said obtaining and recording consent for every sample taken was simply "impractical". He added: "You as an individual almost certainly wouldn't mind your blood sample being used for research if it were anonymised."
Robert Terry, a policy adviser at the Wellcome Trust, said: "The collection of blood is done by hundreds of staff in a hospital. If one of those gets it wrong, who goes to prison?" He stressed that scientists supported the thinking behind the bill, but added: "The consequences may be that huge swaths of current research suddenly fall under a legal obligation and that research is constrained."
The Royal College of Pathologists said its members would stop carrying out additional work such as teaching, making presentations at scientific conferences and publishing their work for fear of prosecution. It said some senior pathologists had considered withdrawing from post-mortem work.
One paediatric pathologist had written to the college warning that pathologists would play safe and avoid taking specimens for microscopy because "the hazards of reaching an unreliable diagnosis (patient complaint, civil proceedings, General Medical Council referral) are less than the hazards of inadvertently using a specimen for something that contravenes the Human Tissue Act (imprisonment)".
The college will press the government to clarify and amend the bill.
'I'M NOT GOING TO RISK BEING A CRIMINAL'
Peter Furness, a pathologist at Leicester General Hospital, fears that, as it stands, the human tissues bill could be "potentially disastrous" for doctors such as him. He thinks the bill's requirements for the use of post-mortem tissue are sensible. But he spends most of his time making diagnoses by looking at tissues from living people, which, he argues, is an entirely different scenario.
"Many of the people are asking for tumours to be removed.
Opinion surveys show most of them regard what is removed as surgical waste," he says.
Professor Furness insists that the Department of Health is wrong to assume many hospitals are already informing patients that their samples might be used for research or teaching. He recalls a meeting in July last year when 50 pathologists from around the country were asked if their trust had such a system in place. "Not one hand was raised," he says.
Professor Furness is alarmed by the threat of imprisonment included in the bill. If it goes through, it will impact on how he does his job.
"If I'm asked to do a teaching session using microscope slides from biopsies I've seen, I'll want concrete affirmation that I have appropriate consent, otherwise I won't do it. I'm not going to risk being a criminal," he says.