The law in Scotland will change from Monday meaning gay couples can adopt children.
At present a gay person may adopt but their partner would not be legally responsible for the child.
According to a recent poll, 47 per cent of the British population is opposed to gay adoption.
Carl Watt, director of Stonewall Scotland, a homosexual lobby group, said: “What all children need and deserve most of all is a safe, secure, loving and stable home environment and same sex couples are equally able to provide this as opposite sex couples.
“This legislation also means that there will be hopefully fewer children in care homes and more with homes and families of their own.”
But his claims were dismissed by Peter Kearney who is a spokesman for the Roman Catholic Church.
He said: “This change is unlikely to have an effect on the shortage of adoptive parents because there are very few same sex couples interested in adoption.
“It would have been better if the Government had launched a campaign to encourage heterosexual married couples to consider adopting.”
Individual adoption by a gay parent has so far been very rare with only two cases recorded in Edinburgh and one in Glasgow.
Mr Kearney also said: “Children need security and stability and civil partnerships and same sex relationships are profoundly unstable.”
The Times reported the results of a Populus poll in July that found 47 per cent of the population are against gay adoption and 49 per cent are in favour.
In June a London-based Roman Catholic adoption agency had to close because of ‘gay rights’ laws forcing it to act against its religious ethos.
The Catholic Children’s Society (Westminster) said the 2007 Sexual Orientation Regulations (SORs) were to blame.
A spokesman said at the time: “We do this with deep regret but have been forced into this position.”
“The trustees are convinced that what is best for children is that they be brought up by married couples. This is shown by research but it is also consonant with the teaching of the Church.”