We are strongly committed to encouraging serious debate over the pressing need for transplant organs

Professor David Kerr, National Kidney Research Fund

Most organs currently used are taken from patients who are clinically dead, but who are being artificially kept alive.

Doctors can use some organs from donors who have just died, but though the practice is not illegal, there are currently no laws to govern it, leaving some doctors wary of the procedure.

In the debate, Kenneth Clarke said: "From time to time there have been doubts raised about the abilities of health authorities, trusts, doctors and others to carry out certain procedures and to be absolutely certain they are within the law.

"No legal challenge has taken place so far. But I'm afraid I think we're living in an increasingly litigious age."

He also called for it to be made plain which relatives should be consulted over consent.

At the moment, the rules say steps should be taken to ensure "no surviving relative " objects to the donation of organs.

But that allows for a distant relative to object.

Mr Clarke wants the relatives who must be consulted to be limited to cohabiting partner, husband or wife, parent and child.

The Bill has to be voted on in another session because there were not enough members in the House of Commons to vote when it was debated.

Presumed consent support

The National Kidney Research Fund (NKRF) found over half the 163 MPs it surveyed supported a system of presumed consent, which has long been favoured by doctors.

It would mean anyone who did not want to donate organs after death would have to opt out.

MPs also back greater use of living donors, for operations such as kidney and liver transplants.

Kidneys are particularly suitable as people can survive with just one.

Professor David Kerr of the NKRF said: "We are strongly committed to encouraging serious debate over the pressing need for transplant organs including the issue of presumed consent for donors, which would be one way of increasing the supply of organs."

The BMA Transplant Partnership, a coalition of 19 patient and medical organisations backed the NKRF's call for a revamp of the organ donation system.

Dr Michael Wilks, chairman of the BMA Transplant Partnership, said: "There is overwhelming support from MPs for change and reform."