It's nothing new, of course, for women to try to get men to take responsibility for the children they beget and for men to try to get out of doing so. There was that courtesan in Balzac who tried to foist the paternity of her unborn child on to no fewer than three of her lovers. That was before DNA tests spoilt all the fun.

Yet the moral problems raised by the fireman who is being pursued by a lesbian couple to support two children he begot by sperm donation seem in a different category from the ones we are used to.

Andy Bathie finds himself chased by the Child Support Agency for £400 a month to support the children that resulted from his donation of sperm to Terri and Sharon Arnold, who were in a civil partnership and wanted to have children. Terri and he had been friends. But when Terri and Sharon split up, Sharon had no financial responsibility for the children because she was not their biological mother.

The girl and boy who were born as a result of Terri and Sharon wanting to play mummies and daddies are now left effectively with a single mother.

Mr Bathie naturally feels hard done by - had he donated sperm to a licensed clinic, he could not now be harassed by the CSA. But if the Government's controversial Bill to regulate embryology and fertilisation passes into law, the legal situation will be very different. Licensed clinics providing sperm will have no obligation to consider the child's need for a father.

Terri and Sharon would feature together on the children's birth certificates. Presumably, Sharon, rather than Mr Bathie, would be pursued by the CSA. And there would be no record of Mr Bathie's part in his children's lives at all.

Would this really be to the good? Gay relationships can, of course, be solid and lasting, but the reality is that most last less long than normal marriages. The Government's plans to place gay parents on the same basis in law as heterosexual parents is based on a fantasy that one relationship is as good as another for bringing up children. Wishful thinking is a bad basis for law.

I'm not sure either that Mr Bathie's attempt to write himself out of his children's lives deserves much sympathy. What he is trying to do is turn fatherhood into gamete donation. But ministers are, in other contexts, straining every nerve to try to make men take fatherhood more seriously. Even those shy souls who donate sperm for money at fertility clinics are being told that the products of their sperm will have the right to turn up on their doorstep and call them Daddy.

Men have often tried to evade the responsibilities of paternity. Only now is the Government in its new Bill trying by law to help them to do it.

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