Family members could no longer have a say over whether their loved ones donate their organs upon death as part of new opt-out proposals.
A consultation on a potential shake-up of the service in England has created the potential for the deceased to make the decision alone.
At the moment, the default position is for organs not to be donated unless the patient opts in.
In any case, medics must seek approval from the dead person's family before pressing ahead with an organ transfer.
But the consultation paves the way for consent to be presumed - even though there is a lack of proof the measure will drive up donation rates - with an option for that permission to be made by the patient without familial input.
Claire Williment, head of transplant development at NHS Blood and Transplant, said: "It is in the consultation paper but whether or not it will happen and what comes out if everybody says the family should never, ever have any role in consent is down to the Department of Health which goes into the law.
"But it's an option."
Keith Rigg, consultant transplant surgeon at Nottingham University Hospitals NHS Trust, said the consultation announcement from Theresa May in October last year came "out of the blue", and said it might have been better to wait for results from a similar opt-out scheme launched in Wales in 2015.
Latest figures show there were 33 cases in Wales where deemed consent was applied last year, and in 13 cases the families did not support the decision to donate an organ.
It indicates a higher (60%) donation rate with presumed consent in Wales than the opt-in model in England (just under 50%), although the number of cases is small.
Mr Rigg said cultural and religious beliefs, and not knowing a patient's preference, are the main two obstacles for increasing donation rates.
He said: "Everyone talks about Spain as being the country with the highest organ donation rates in Europe ... (but) the main changes were seen about 10 years after the changes to the legislation.
"It's the changes in the infrastructure (and best practice such as identifying all potential donors, and best use of retrieval teams) that have made the most difference, rather than the legislation.
"There is that view that opt-out is seen as the best thing since sliced bread and that it will sort the problem out.
"But there is a much wider perspective. Assuming opt-out does come in, it's hard to know how much difference that will make."
Dr Dale Gardiner, deputy national clinical lead for organ donation at NHS Blood and Transplant, and an intensive care consultant at Nottingham University Hospitals NHS Trust, said the point of the consultation was to "minimise the grief of the family".
He said: "If a person has an opt-out, it makes it so much easier (for family) to say: they would have opted out, I don't have to think about it too much, I've got so much else happening and just say 'yes'.
"If that makes their grief easier, that's a good thing. I want a system that supports the family in this terrible situation but actually respects the wishes of those who've died."
The consultation, which has received 11,000 responses so far compared with "around 300" on previous Department of Health consultations, closes on March 6.