Doctors have called on the government to change the law on organ transplants.
There is a serious shortage of organs in the UK
They say outdated laws are preventing thousands of people from having potentially life-saving transplant surgery each year.
Grey areas in the law mean doctors are only able to obtain organs from certain patients.
Ministers are currently considering proposals to introduce new rules, which could see more organs becoming available.
There is a serious shortage of organs in the UK. Over 5,600 people are currently waiting for transplants.
A Department of Health consultation document Human Bodies Human Choices published last year outlined a number of different ways of boosting the number of organs available for transplant.
Officials are now considering responses to the document as part of plans to change the law.
However, the British Transplantation Society criticised the government's failure to change the law.
Dr Peter Rowe, its chairman, said: "The law's long overdue for an overhaul and they have had long enough."
He added: "We would like the Department of Health to be more pro-active in some of these grey areas and give a clear lead."
Mr Keith Rigg, a consultant transplant surgeon at Nottingham City
Hospital, said the failure to change the law was frustrating doctors.
"Nobody's prepared to make a decision one way or the other until the new law
is there, so there is a sense of frustration," he said.
A Department of Health spokeswoman said proposed changes to the law would be published shortly.
"We are considering responses to the consultation document. We want to make sure we get it right. This is a very complex area. The law hasn't changed since 1963," she told BBC News Online.
Doctors believe updating the law on organ transplants will help to tackle the rise in so-called "transplant tourism".
A growing number of people pay people in countries like India for organs each year because of the shortage in the UK even though it is illegal.
A recent survey of 12 UK transplant units identified 29 cases where patients have
gone abroad to buy a kidney. Half of these organs failed and others had led to the patient becoming ill.
There have been calls for ministers to introduce a law which would see all adults considered potential organ donors unless they have expressly said otherwise.