The battle over same-sex marriage returned to the courts yesterday for the start of a three-day hearing in the Court of Appeal.

The Attorney-General will argue that former Chief Justice Ian Kawaley erred in a ruling that reopened the door for same-sex marriage.

But same-sex marriage campaigners will maintain the ruling was correct and a clause in the Domestic Partnership Act to specify marriage as between a man and a woman is counter to the Constitution.

Arguments will continue in court today.