A LANDMARK legal ruling which gives a lesbian couple the same parental rights as heterosexuals was condemned yesterday by family groups and church leaders.

The decision means that the women, known as Pam and Natalie, have full responsibility for their children and are considered a family unit by the courts.

The move sparked outrage from family groups which said the ruling could harm the children's development, but was hailed as a ''step in the right direction'' by gay rights campaigners.

The women are the first lesbian couple in Scotland known to have parental rights granted.

Valerie Riches, founder of the group Family and Youth Concern, yesterday criticised the ruling and said she feared it could open the floodgates for more cases: ''This is morally wrong. Nobody is thinking of the welfare of the children. It is simply about the adults and what they want,'' she said.

Pam, who has a five-year-old son, David, and Natalie, who gave birth to Cameron following artificial insemination, now have rights over each others' children in the same way as a married couple.

The ruling also means that the children have three parents as the case was not appealed by David's father, who separated from Pam three years ago.

Following the decision, by Sheriff Noel McPartlin at Edinburgh Sheriff Court on March 19, gay rights campaigners are encouraging more couples to take similar action.

Tim Hopkins, chairman of the Gender Equality Network, said: ''There are hundreds of families in Scotland parented by gay people and I hope this decision encourages many more to try and win parental rights for children they are already parenting.

''We are delighted by this judgment because it offers the children of same sex couples the same stability and legal protection that children of married couples or unmarried couples can enjoy.''

However, Peter Kearney, a spokesman for the Roman Catholic Church in Scotland, said the judgment created ''a bizarre situation where unmarried same-sex couples have more parental rights than many unmarried fathers.''

He called for a clarification of the law in the light of the case, which he said ''flew in the face'' of a sheriff court judgment last month, which ruled that a lesbian couple did not constitute a family group.

Mr Kearney added: ''The natural social and biological ideal environment for children to develop in is with married parents. We know the advantages and benefits of that.''

The women launched their action when they discovered that Pam, the boys' main carer, could not give permission for Cameron to have medical treatment.

Wendy Sheean, lawyer for the couple, said: ''Family is a broad concept that has to take into account the reality of who is caring for the child, not the biology of its parents.

''The sheriff took a flexible, enlightened approach to the legislation and took account of the reality of the situation.''

Natalie and Pam said they did not intend to strike a blow for gay rights in Scotland, but wanted to make a stand for the rights of their own children.

The case will now be cited by a lesbian couple in Glasgow who recently went to court to stop a gay sperm donor who fathered their child from winning custody.

They are appealing against the decision by Sheriff Laura Duncan to give parental rights to the donor, saying that women did not constitute a family unit.