Children of sperm and egg donors should be allowed to trace their biological fathers, the government has announced.

The new regulations will not be retrospective - only people who donate sperm, eggs or embryos from April 1, 2005 will not be granted anonymity, although they will still have no financial or legal obligations towards the child, who will be able to request the information from aged 18.

Shadow health secretary Andrew Lansley said: "The law at the moment gives anonymity to sperm and egg donors, while giving children a right to information about their genetic origins if they need treatment, or about their ability to marry another person.

"Proposals to remove this right to anonymity in the future will run a serious risk of undermining prospects for the supply of sperm and eggs for donation. The opportunity for some couples to seek fertility treatment may therefore be damaged.

"The prospective benefit to some children who wish to know about their biological father or mother (not their legal father or mother) - which would in any case require highly sensitive counselling - must be weighed against the harm to couples wishing themselves to give positive parenthood to children of their own.

"So far, I believe the case for a change in the law has not been made and, while this will be a matter considered in the House of Commons on a free vote, I will oppose this change."

Forum Response: Human Fertilisation and Embryology Authority

Suzi Leather, chair of the HFEA, said: "We consider that sharing information about origins with our children is part of responsible parenting.

"Although it is right to respect the guarantees of anonymity that have been given to donors in the past, it also seems to me wrong that the state has information about someone's origins which they want and cannot have. Secrecy in adoption has been discredited and secrecy in assisted reproduction will come to be too.

"It is the decision which donor-conceived people as well as the HFEA and many other organisations wanted. In years to come there will be very many people who will be profoundly grateful to the government for taking the steps which will allow them to know who their biological parents are."

Forum Response: CARE

Roger Smith, head of public policy for the Christian charity CARE, told ePolitix.com: "We welcome the government's decision to remove future anonymity for donors of sperm and eggs.

"We've been urging the government to do so on compassionate grounds - research has clearly shown that children concieved by donor sperm suffer trauma when faced with secrecy over their origins.

"It is now universally accepted that adopted children have the automatic right to find out their genetic and biological heritage. It cannot be right to then deliberately deny that same right to the children of donor gametes. We are delighted that the government now acknowledges this.

"Children have the right to choose to have fundamental information about their existence and their genetic heritage. Such knowledge is also crucial to their development of a secure identity."