A major ruling by the UK High Court gives childless couples the right to pay fees as a well as expenses to surrogate mothers to have babies for them.

The ruling, by a senior family court judge, allowed a British couple to keep a newborn child even though they had technically broken the law by giving more than “reasonable expenses” to the American natural mother.

The ruling comes after it was suggested that a significant increase in the fees paid to sperm and egg donors. Reports suggested that the UK’s Human Fertility and Embryology Authority is considering adopting the Spanish system which would see the payment cap lifted to £800 from the present level of £250. Critics said the proposal represented a further commercialisation of sperm and egg donation.

According to Mr Justice Hedley, the current rules on payments were unclear. He added that the baby’s welfare must be the main consideration.

Only in the “clearest case” of surrogacy for profit would a couple be refused the necessary court order to keep the baby, he said.

His comments, among the first in recent years on the subject by a senior legal figure, are likely to lead to new calls for the existing law, rushed through more than 20 years ago after a famous case, to be tighten up in order to discourage “rent a womb” commercial surrogacy.

Mr Justice Hedley said in the High Court on Wednesday: “It is clear to me that payments in excess of reasonable expenses were made in this case.”

In addition, the money paid to the surrogate mother had been described as “compensation” rather than expenses.

However the judge also said that the concept of reasonable expenses was “somewhat opaque” and added: “Welfare is no longer merely the court’s first consideration, but becomes its paramount consideration.

“The effect of that must be to weight the balance between public policy considerations and welfare decisively in favour of welfare.

“It must follow that it will only be in the clearest case of the abuse of public policy that the court will be able to withhold a (parental) order if otherwise welfare considerations support its making.”

However, Mr Justice Hedley did warn that the courts would continue to consider the amount of money paid in each individual case, to ensure that a market is not established.

“Notwithstanding the paramountcy of welfare, the court should continue carefully to scrutinise applications for authorisation (of payments)… with a view to policing the public policy matters…and that it should be known that that will be so.”

A law regulating surrogacy was introduced in Britain in 1985, after Kim Cotton was paid £6,500 to carry a child conceived using her own egg but the sperm of a man whose wife was infertile, in what is known as “straight surrogacy”.

Under the Surrogacy Arrangements Act 1985, companies were banned from brokering deals between couples and potential mothers for profit. All arrangements have to be based on trust rather than money, and are not legally binding. Only “reasonable expenses”, which now can average £15,000, are allowed and must be agreed upon by the parties.

In 1990, another law introduced the system of Parental Orders which couples must obtain following the birth in order to be regarded as the surrogate baby’s legal parents, rather than the natural mother.

It is estimated that each year 70 women in Britain have surrogate babies, but many more couples wishing to start a family now travel to countries such as India where the “reasonable expenses” will be far lower.

In the current case, the unnamed British couple had made contact with a woman in Illinois, where no restrictions on payments to surrogate mothers apply. Her baby had been allowed to enter Britain on temporarily on a US passport, but the judge granted a Parental Order so it can now stay in the country with its new parents.

Mr Justice Hedley agreed that the criteria, which also require that the surrogate acted of her own free will and that one of the couple must be a biological parent of the baby, had been “fully met” by the “most careful and conscientious parents”.

However some have criticised the implications of his comments that payments above “reasonable expenses” were acceptable.

Andrea Williams, director of the Christian Legal Centre, said: “Children are not commodities to be bought and sold. It is not the case that everybody has the right to a child, whatever the cost.

“The regulations that we have in this place regarding surrogacy are supposed to ensure that there is no element of profit in the whole process.

“Once a line is crossed within the system where profit has essentially been made, this leads to a weakening in the regulations and the effectiveness of the law and will lead to more situations like this.”