BBC News Online invited representatives from both sides of the debate on human cloning to set out their arguments for and against - Dr Simon Best, managing director of Geron Biomed, the commercial arm of the Roslin Institute which cloned Dolly the sheep, and Peter Garrett, Research Director of the anti-abortion campaign group Life.

Dr Simon Best

Peter Garrett

For scientists to be allowed to clone human embryos and convert these genetic twins into tissue and organs, or to use them for experimentation, is the ultimate violation of the ethical principle that human beings must always be treated as ends in themselves and never as means to an end.

From the moment a complete human embryo comes into existence, its status as a unique new member of our species must be acknowledged and respected.

Attention needs to be drawn to the fact that legalising so-called therapeutic cloning will provide the ideal bridge across which scientists and pharmaceutical companies will march toward full-pregnancy cloning. This will yield massive profits as individual cloned children are sold for thousands of pounds.

I also have a deep conviction that so-called therapeutic cloning is really a form of sibling cannibalism. Sick patients are being persuaded to allow twin and triplet "copies" of themselves to be deliberately produced and then destroyed. The clones are killed when they are converted into the requisite transplantation tissue.

The announcement that the government is not yet going to legalise human cloning is a victory for common sense, and the result of extensive activity by those opposed to human cloning.

Ministers have probably realised that public disquiet on this issue is at an all-time high, and the decision to take a pause for thought is most welcome. The government is listening to the voice of public concern, and this is a good thing.

Dr Simon Best

Back to Peter Garrett

Therapeutic cloning has the potential to develop treatments for a wide range of degenerative diseases - such as diabetes, Parkinson's, Alzheimer's, hepatitis, liver cirrhosis and cancer - for which none currently exist.

In diseases such as these, cells die and/or lose their normal function, and the body loses the ability to replace them. Therapeutic cloning opens up the possibility of providing new populations of healthy cells to replace these.

To produce replacement cells, it is necessary to start with special cells called stem cells. These have an unlimited ability to divide and the capability to turn into virtually all cell types and tissues in the body.

At the moment, the only way of doing this is to extract them from early stage pre-embryos - typically at the 5-6 day stage.

Stem cells were first derived from spare pre-embryos donated following successful in-vitro fertilisation (IVF) procedures. To create cells that will not be rejected by a patient, it is currently necessary to use the nuclear transfer cloning technique that produced Dolly the sheep to make a new pre-embryo from which to derive fresh supplies of the patient's own cells.

We now believe that it is appropriate to start research using current techniques to confirm that the potentially enormous therapeutic benefits of this technology can actually be realised in practice.

This would not require the culture of embryos beyond the 14-day stage and this has been approved for some time in the UK in the case of IVF treatment.

IVF has allowed several thousand families to have healthy children who would not otherwise have been able to do so, and we believe that the same principles should apply in the case of therapeutic cloning given the enormous benefits that may be achieved.