Leading fertility campaigner Baroness Warnock is heading calls for children conceived using donor sperm to be allowed the legal right to trace their fathers.

But some people fear a reduction in the number of sperm donors if the anonymity factor is removed.

Others believe children conceived in this way should have a right to know their background and genetic history.

BBC News Online presents the arguments of two clinicians on either side of the debate.

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Professor Ian Craft, director of the London Fertility Centre:

I think the Baroness is wrong - if people who donate want to remain anonymous I do not think they should be forced to be identified.

I think it would definitely lead to a reduction in the number of donors.

These people should not be prevented from taking part in something which is very important.

I think it is political do-goodness gone wrong. We should not have a police state.

When the process of sperm donation first began in the mid 1980s anonymity was thought to be in line with general public opinion - I don't think that has changed.

Also, why should children born in this way be given more rights than children born through natural conception?

There are enough hurdles in front of would-be parents seeking help without this

Professor Ian Craft

Children born naturally often have no knowledge of their fathers and they are never told.

What about the rights of the couples who opt for assisted fertilisation?

We give people the right to terminate a pregnancy and destroy a child, yet not give them the right to rear a child?

There are enough hurdles in front of would-be parents seeking help without this - fewer donors coming forward would mean they would have to wait even longer.

'Better screening'

To change the law for sperm donations would have to have a bearing on egg donations too.

Professor Craft: "Donations would be reduced"

I think it would mean fewer donations of both and this would have a dramatic effect on fertility services which are already struggling with a lack of donations.

It would also discriminate against poorer couples who rely heavily on going through the NHS for assisted fertilisation.

They would have no other choice but to wait longer, and would perhaps never have the chance to have children in this way.

I have always argued for better screening of donors, preferably through a national organisation like the Department of Health, so that you would gain all the necessary medical and genetic history.

You can have all that knowledge without knowing the person.

Dr Mohamed Taranissi, medical director of the Assisted Reproduction and Gynaecology Centre in London:

Dr Taranissi: "I would want to know"

We now know more about genetic make-up and to know some of this might be very important to the child or when they become an adult.

You would not know this genetic information unless you took extra samples from the father - you cannot do this all at the beginning and study all the genetics.

Looking through every gene in the body is not practical - it's not like leaving your name and address.

'Exaggerated'

I don't think it would mean a lack of donations.

There is already a lack of donations and in Scandinavia, although the immediate impact resulted in fewer donations this does not seem to have made a big difference in the long term.

It should be part of the child's welfare rights to know who their real father is

Dr Mohamed Taranissi

These claims that it will put people off donating have been exaggerated.

I don't believe it would have an effect on egg donations.

This is a different matter and a much more complicated process - there are enough reasons to put people off donating in this way already.

Opinions have changed since 30 years ago and for a good reason.

Medical reasons

There would not be any repercussions for the sperm donor.

If they are not willing to take on extra responsibility, no one will force them.

It should be part of the child's welfare rights to know who their real father is - I would have wanted to know if it was me.

Perhaps there could be a compromise, in that the identity is only revealed for specific medical reasons.

But I think that the couples who seek this treatment should not just think about it from their own point of view and should consider the rights of the child.