The government is examining ways to allow test tube children to identify their genetic parents.

At the moment, many children born following fertility treatments are conceived using donated sperm or eggs.

But the donations are made with complete anonymity and the child has no right to track down the man or woman who donated their reproductive material.

Fertility specialists warn that removing the right to anonymity would deter people from donating, further contributing to a shortage of sperm and eggs in the UK.

Step towards change

The Department of Health confirmed that it was looking at the issue and would publish a consultation paper in the autumn.

However, a spokeswoman stressed that it would only be the first step towards any change in the law.

Any law allowing children to uncover the identity of genetic parents is unlikely to apply to donors who gave before the change on the understanding that they would remain anonymous.

Tim Hedgeley of the National Fertility Association warned that the move was bad news for donors.

"This may be a victory for children, but it certainly is not for the donors," he said.

"Their rights have to be protected too. People already give for altruistic reasons and now they are going to be hammered for it."

Identity clause

Internationally there have been growing calls for anonymity to be lifted, and some clinics in the US insist that donors meet their genetic offspring.

Pacific Reproductive Services in California, for example, asks donors to agree to a meeting with any child conceived using their tissue.

The one-off meeting is scheduled to take place when the child reaches 18, and contact does not need to be maintained after this time, although of course by that stage the anonymity has been broken.