The research also found that just 3.75 per cent of children adopted in England in 2010 were adopted by same sex couples.
Barnardo’s chief executive Anne Marie Carrie argued that children in the care system are continuing to lose out on potential parents because of "a disturbing and prevalent belief system".
"Society’s attitude plays a pivotal role in discouraging people from considering adoption," she said. "The idea that gay parents are second best must be challenged. To suggest that a same-sex couple is not as able to raise a child as a heterosexual couple is at once absurd and unsubstantiated."
"To continue to discourage potential adopters simply because of their sexual orientation is severely diminishing the chances of securing loving, stable homes for the children who are waiting. This debate needs to be urgently raised and myths surrounding how sexuality, race, marital status and gender can affect your parenting dispelled."
Adoption UK chief executive Jonathan Pearce said more time should be spent thinking about how best to support adoptive families, rather than worrying about people’s backgrounds.
"There is a certain irony that gay/lesbian couples are being adversely judged in this way," he said.
"After all, children from care are placed for adoption in the majority of cases because they have been abused and neglected in their birth families, the overwhelming majority of which would have been heterosexual parents. We don’t then conclude that all heterosexual parents are bad parents."
He added that gay and lesbian adoptive parents are part of an invaluable community of adopters that take on the parenting of abused and neglected children, and as such should be celebrated for that role.
"From Adoption UK’s own recent survey on adopters’ experiences of being recruited and assessed, it is clear that for up to one-third of adopters there are issues of prejudice and discrimination, whether in relation to their race or ethnicity, sexuality, marital status or financial situation," he said.
"A person’s ability to parent is not based upon any of these factors. At a time when we are trying to recruit and support many more adopters to be parents for the 4,000 children that we know need adopting from care, it is a gross dereliction of duty that we cannot stamp out these misplaced prejudices. How will we explain this in the future to those who spend their childhood in care, but could have benefited from an adoptive family?"
