Professor Campbell, chairman of the Human Fertilisation and Embryology Authority - which regulates fertility clinics and embryo research - said the issue raised serious ethical questions.
Launching the authority's consultative document, which sets out arguments for and against selection, he said decisions had to be made on whether baby selection services would be a 'slippery slope' towards selecting gender for frivolous reasons, or be a reasonable exercise of choice made possible by scientific advances.
He said that Tom Sackville, Under-Secretary of State for Health, had asked for a copy of the document. The Government could decide to amend the Human Fertilisation and Embryology Act 1990 to cover the issue.
Yesterday the authority brought forward its consultation document on sex selection in the wake of controversy surrounding the opening of a north-west London clinic that offers sex selection for pounds 650.
But since the treatment does not involve the use of donated sperm or eggs, or creation of embryos outside the body, it does not come under the jurisdiction of the authority or the Act.
Professor Campbell said the authority would advise the clinics it licensed not to embark on gender selection for social rather than medical reasons until the authority or the Government had made a decision.
One licensed clinic provides medical gender selection - which is permitted. This takes place after in vitro fertilisation to avoid the birth of babies handicapped by a gender-linked disease such as haemophilia, which affects boys. New legislation would be needed to regulate social sex-selection clinics, Professor Campbell said. The consultation period will continue until 31 May. He said the authority wanted to hear from the public as well as scientific and medical organisations.
Dr John Habgood, the Archbishop of York, last night called for 'great moral caution' against adopting such techniques as a normal part of medicine, although he could see no ethical objection to selection for medical reasons.
The London Gender Clinic, in Hendon, is run by Dr Alan Rose, a clinical pathologist, and Dr Peter Liu, a biochemist, who use a technique based on one developed by Dr Ronald Ericsson in America - where there are said to be about 60 clinics in operation.
Dr Rose said the process takes about four hours. Couples attend when the woman is in the fertile days of her cycle and the man produces semen. The sperm are filtered through albumen in which the 'male' sperm carrying the y chromosome swim more strongly than the x chromosome 'female' sperm, and can be filtered out. The woman is artificially inseminated with selected sperm.
He said: 'I think if a family wishes to have a balanced family of two females and two males rather than four girls . . . if the choice is there they should be allowed to make it.
'We interfere with nature all the time - contraception is a gross interference but that has come to be accepted by large sections of the population.'
The clinic has laid down its own guidelines, providing the service only to married couples who already have a child and asking them to sign an undertaking to see the pregnancy through regardless.
Claims of effectiveness vary, but are between 70 and 80 per cent for male babies and 60 to 70 per cent for female babies - against nature's even odds.Reuse content