Women could be allowed to donate their eggs for therapeutic cloning research under new rules to be considered by the fertility watchdog.
Women could donate eggs even if they are not undergoing fertility treatment
So-called 'altruistic' donation is to be debated by the Human Fertility and Embryology Authority on Wednesday.
Human eggs are used in the creation of embryos which from which stem cells can be derived.
But critics say altruistic donation would mean women undergoing an unnecessary and risky procedure.
There are also concerns because many feel the benefits of such research are, as yet, unproven.
At the moment, researchers are permitted to ask women who are undergoing fertility treatment if they are happy to donate 'spare' eggs produced when their ovaries are stimulated during IVF, which they do not need.
These can be used in research into areas such as freezing eggs. But the HFEA has to consider the issue when donated eggs would be used to create embryos.
Scientists say there is a shortage of eggs for such research, and have asked for women to also be able to choose to donate specifically for that purpose.
Altruistic donation is already allowed to help infertile couples conceive.
In the cloning process, the nucleus of an adult cell is placed into an egg that has had its own DNA removed.
These eggs are then stimulated to develop into an embryo for a few days.
The embryonic stem cells which are then produced are genetically identical to the patient who donated the cell, enabling them to be used for treatment without rejection.
It is hoped ES cells could one day treat conditions such as Parkinson's disease.
However, there are concerns over the egg donation process.
It can cause fertility problems, and involves women taking hormones that boost egg production.
It carries the risk of ovarian hyperstimulation syndrome, which in some cases can cause kidney damage and lead to death.
In a paper to be considered in a public HFEA meeting, its research committee said allowing women to choose to donate their eggs could benefit research - and enable the donor to feel they had made a positive contribution.
However, the paper does point out donors would be undergoing a medical procedure for unnecessary risk, and there was the potential for regret later on in life if their own fertility was affected.
The report recommends that, to guard against this, women should only be allowed to donate if they have completed their own families.
'Adverse publicity risk'
In the recent scandal over the work of South Korean scientist Woo Suk Hwang, it emerged that he had used eggs from junior members of his team, raising concerns over coercion.
To guard against these kind of concerns, the HFEA suggests friends and family of scientists would be permitted to donate eggs, but would be given independent counselling to ensure they were acting entirely voluntarily and have not been pressured into it.
Scientists working on a particular research project would be barred from donating their own eggs to their own laboratories.
However they would be allowed to donate their eggs to a different research group.
James Healy of the HFEA said it was aware researchers at Newcastle and Edinburgh universities were keen to be able to obtain donated eggs.
The authority has accepted there may be "adverse publicity" if it gives the go-ahead to altruistic donation.
But Mr Healy said: "As a responsible regulator, we have to look at this closely."
He added the outcome of the meeting was not a "foregone conclusion" and would be decided based on the views of the authority board and members of the public expressed there.
Michaela O'Sullivan, of the pro-life charity Life, said: "It is disgraceful that the HFEA is to entice women to undergo invasive and risky operations in order to facilitate experimental research that offers no immediate hope of cures."