An academic study into the impact of children being raised by gay parents found that children living with two mothers have the same social competence as a child raised by a straight couple.

The 2003 report was only released by Canada’s Justice Department after a freedom of information request by its author.

Professor Paul Hastings of Concordia University was commissioned by the Liberal government as the country was discussing same-sex marriage, now legal in Canada.

“A few studies suggest that children with two lesbian mothers may have marginally better social competence than children in ‘traditional nuclear’ families, even fewer studies show the opposite, and most studies fail to find any differences,” says the 74-page study, according to canada.com

A debate on same sex marriage was held in November in the country’s Parliament after a manifesto pledge from Conservative Prime Minister Stephen Harper that a debate on banning gay marriage in Canada would be held.

His bid to ban gay marriage failed.

Professor Hastings said he believes that the study was being held back from being published when Harper’s Conservative government came into office.