The Human Tissue Bill continues to pose a threat to medical advances, the Royal Society has warned.
Research could suffer from law changes
It said the government had failed to take the concerns of scientists or doctors on board before publishing a revised version of the Bill.
It said the bureaucracy required under the law was prohibitive and would stop research into cancer and heart disease.
Health Minister Rosie Winterton insisted the Bill would take their concerns into account.
The law was drafted in response to the Alder Hey and other scandals when it was revealed that doctors had been taking and storing organs and tissues from dead patients without permission.
The revised version of the Bill is to be presented shortly in the House of Lords.
Lord May, president of the Royal Society, said the government had ignored the concerns of scientists and doctors.
He said: "We wholeheartedly and unreservedly support the Human Tissue Bill's aim of increasing public confidence over the collection and use of human tissues and organs.
"But the government is oversimplifying the issues and making the need for consent too broad. It's like using a sledgehammer to crack a nut.
"No distinction is made between tissue samples taken during routine diagnostic tests at one end of the scale and the removal of organs during post-mortem at the other."
He is also concerned about existing collections of stored tissues, which are exempt from the new legislation but will be subject to a code of conduct from the Human Tissue Authority.
"This additional guidance could place restrictions on the use of these collections but will not be subject to Parliamentary scrutiny and researchers will have no opportunity to comment, even if it is too restrictive," Lord May said.
The Royal College of Pathologists has said it backs the law change though it is concerned about some of the wording.
It says the burden of securing consent may prevent some doctors from taking part in research.
Professor James Underwood, president of the college, said: "The college shares Lord May's concerns about the unintended consequences of the Human Tissue Bill, unless it is amended as we have suggested.
"We hope that pathology and research expertise will be represented on the Human Tissue Authority to help draft codes of practice that satisfy both the need for human tissue research and the interests of patients and their families."
Rosie Winterton said: "Scientific research is vital. That is why we have been talking to the medical and scientific community about their concerns.
"We are looking at ways of addressing them in the Bill but maintaining the balance between the rights of individuals to be consulted and the need for vital medical research."
However, Shadow Health Secretary Andrew Lansley, said the Bill needed to be amended.
"The Department of Health would be wise to listen to the prime minister's former science advisor who has repeated the concerns which we and others in the medical and research community have long been saying."