Children brought up by gay couples are healthier and get along better with their families, according to the initial findings from the world's largest study on the children of same-sex parents.
The research, which studied the wellbeing of 500 children in Australia, found that the self-esteem of children and the amount of time they spent with their parents was no different from the rest of the population.
However children of same-sex couples scored higher for overall health and family cohesion, so overwhelmingly in fact, that researchers said it would only occur by chance less than 1 in 10,000 times.
Researchers still don't know why children fare better with same-sex parents, but the lead author on the Melbourne University study, Dr Simon Crouch, offered his opinion on the findings.
"Because of the situation that same-sex families find themselves in, they are generally more willing to communicate and approach the issues that any child may face at school, like teasing or bullying," Dr Crouch said.
"This fosters openness and means children tend to be more resilient. That would be our hypothesis."
The research directly contradicts 'evidence' offered by Lords, religious leaders and ministers, who have all opposed gay marriage on the basis it would be harmful for children.
A letter from Bob Woollard, the chairman of Conservative Grassroots, called on peers to “defend our freedoms” by opposing the Bill on same-sex marriage, which was passed through the Lords on Tuesday night.
Mr Woollard said: “The Prime Minister believes that enabling same-sex couples to get married will strengthen — not weaken — family ties.
“In fact, all the evidence from countries that have introduced this legislation over the last 10 years shows that marriage is further devalued in the eyes of all and the tie between marriage and bringing up of children is seriously weakened.”
As the bill was passed through the Lords, gay marriage was accused of having a "destabilising and confusing effect on children" and Lord Indarjit Singh said gay marriage would lead to children being "neglected."
The Archbishop of Canterbury has also warned that the same-sex marriage bill would create "different and unequal" forms of marriage that will undermine family life.
The findings of the latest study is supported by long-term research published in 2010, which showed that children raised by lesbian parents develop into psychologically healthy teens and have fewer behavioural problems.
At the time researcher Nanette Gartrell at the University of California said: ''Contrary to assertions from people opposed to same-sex parenting, we found that the 17-year-olds scored higher in psychological adjustment in areas of competency and lower in problem behaviors than the normative age-matched sample of kids raised in traditional families with a mom and a dad,"