Experts advising the Government have rejected plans for a new system of "presumed consent" organ donation.
A report from the Organ Donation Taskforce said there was insufficient evidence to support the change, which would make people automatic organ donors unless they choose to "opt out".
"Presumed consent" was not expected to increase organ donation rates and might cause "significant complications" said the panel, after an extensive investigation into the practical legal and ethical issues involved.
One of the chief worries was that an "opt-out" scheme might undermine public trust in healthcare professionals and actually reduce organ donation rates.
There were fears that people might think the care of loved ones could be compromised by the pressing need for transplant organs.
The complexity and cost of a "presumed consent" system were other factors not in its favour.
Evidence from other countries suggested "opt out" systems made little difference to organ donation rates, said the experts.
Prime Minister Gordon Brown and the chief medical adviser are both known to be in favour of an "opt out" system, believing it would help reduce the chronic organ shortage and save lives.
An estimated 8,000 people in the UK need an organ transplant but only 3,000 operations are carried out each year. Every year a thousand people die waiting for a transplant.
Following publication of the report, Health Secretary Alan Johnson announced the launch of an organ donation awareness campaign aimed at recruiting nearly half the population to the organ donor register.
