The Human Fertility and Embryology Authority (HFEA) believes that the current level of remuneration - 250 pounds per donation for "reasonable expenses" and loss of earnings - could be deterring donors.

Meanwhile, demand from infertile couples for donated eggs and sperm is steadily rising. Up to a seventh of British couples have problems conceiving.

Prof Lisa Jardine, the chairman of the HFEA, said: "We know that many people are facing long waiting lists at clinics because of a shortage of donors. We want to ensure that we have the best policies in place so that there are no unnecessary barriers in the way of those wishing to donate while protecting those who are born as a result of donation."

In Spain, which has much higher donation levels, women are given a payment of 900 euros (about 760 pounds).

In Britain, women can opt to "egg-share", donating their eggs in return for IVF or other fertility treatment worth thousands of pounds.

This type of donation makes up 40 per cent of contributions. The revised level of cash compensation could be raised to be in line with this - although some experts fear that raising the level too high could attract donors purely for financial reasons rather than for the public good.

The HFEA is starting the public consultation process, which is being carried out online, today.

The findings will be presented to the HFEA board, which will draw up new regulations, in July,

Tony Rutherford, the chairman of the British Fertility Society, warned against setting the level of compensation for women too high.

Paying them the cash equivalent of the value of fertility treatment given to "egg-sharers" would be too much, he said. "That clearly becomes a financial incentive. If that happens, I think there's a real danger that we would lose the altruistic reasons for donation."

However, Mr Rutherford thought the current level of remuneration was too low for women, who had to undergo "at least six hospital visits, injections, a series of appointments and counselling" when donating.

The HFEA consultation will also look at whether the limit on how many families can use the sperm from any one donor, should be changed.

At the moment, up to 10 families can use one donor's sperm, with each able to have as many offspring as they like with it.

The limit is to minimise the chance of any resultant children unknowingly having incestuous relationships and conceiving offspring.

However, Prof Jardine said that the way the clinics worked meant the 10-family limit often resulted in only two or three families using the sperm.

"That's tremendously wasteful," she said. The limit could be raised to 25.