The controversy over organ donations may have left some people confused, so I want to set out the position.

First, are organ donations a good thing, and does Judaism approve? The answer in general is yes. Saving a life is a fundamental imperative in Judaism and, if we can do so without endangering our own lives, we should.

There are two kinds of organ donations that do not pose problems in Jewish law. There are organs - a kidney for example - that can be taken from a living donor, who is taking little risk and remains healthy. Currently, 53 per cent of all donors come under this category. We commend such donations and would encourage them wherever possible.

At the other extreme, there are organs that can be taken when the heart of the donor has ceased to function, for example corneas and, again, kidneys. Currently 35 per cent of kidney transplants fall into this category. Here, too, Judaism commends such donations.

These two categories combined cover approximately 70 per cent of all current UK organ donors. Jewish law permits us to be donors in these situations and, if we can, we should. To do so is a mitzvah of the highest kind, saving a life.

Everyone would agree that you may not remove vital organs of someone still alive

What, then, is the controversy about? It has to do with the definition of death. Today, doctors use brain-stem death as one way to define death. Some halachic authorities accept this in Jewish law. But some do not. Instead, they argue that, in Jewish law, death is determined by cessation of cardio-respiratory activity. Thus, if a patient is brain-stem dead but his or her heart continues to beat, they believe we cannot say clearly and unequivocally that the person is dead.

This makes a difference in some organ donation situations, when the question is: may we remove the vital organs of a person who is brain-stem dead but who - if life is measured by cardio-respiratory activity--is still alive.

Everyone would agree that you may not remove the vital organs of someone who is still alive to save someone else's life. That would be committing murder. In such cases, the criterion by which death is diagnosed is all-important to the halachic permissibility of removing a vital organ. To repeat, however, this is involved only in a minority of cases.

So what is the halacha? Since the earliest days of transplant surgery, halachic opinion has been divided. As I have outlined, there are significant voices on both sides. While not impugning the integrity of those who accept brain-stem death as well as cardio-respiratory to define death, those who accept only the latter have major concerns about the use of brain-stem death as definitive. And they say: if we are in genuine doubt, would it not be better not to risk that we might be killing someone who is still alive?

Precisely because of the seriousness of the concerns of those who require cessation of cardio-respiratory activity as the only criterion of death, the London Beth Din refuses to dismiss them, while encouraging organ donations in all other circumstances. This is not a concern of Jews alone. It is shared by other faiths and by some secular ethicists.

Does this mean that religious Jews should not register as organ donors? We will be speaking to the UK transplant authority to urge it to make provision within its procedures to accommodate these issues, so that within our community, registering with the UK transplant authority can be extended. This would be of help to members of all faiths, and it would be in line with current medical practice generally, which takes cognisance of people's religious, cultural and ethical differences, allowing all faith communities to support organ donation.

Does the current situation open Jews to the charge that they are willing to receive organs but not donate them? We encourage Jews to donate organs wherever possible. A good society is one in which organs are available according to need, and donated according to conscience. That applies to Jew and non-Jew, religious and secular. Even those who do not accept brain-stem death would still be able to donate organs in 70 per cent of cases, and a small addition to the procedure will allow all Jews to register. I will myself, and will encourage others to do so.

Plans are already under way to establish a Jewish bioethics-forum where rabbis and doctors can meet regularly to discuss how new biomedical developments can be taken into account in our rulings in Jewish law. Whatever our view on the criterion of death, we should all do our share in saving and honouring life.