Perth's newly installed Catholic Archbishop has weighed into the same-sex marriage debate for the first time, saying politicians who attempt to change the law to have it recognised are misusing their power.
Archbishop Timothy Costelloe, writing in Catholic newspaper The Record, said governments did not have the right to "dismantle" the institution of marriage because they had not created it.
"Marriage is perhaps the oldest human institution we know of," he said.
"It certainly pre-existed modern Australia and its parliamentary system and, indeed, pre-existed all parliaments.
"This essential link between marriage and the family, and the right of children to be raised by their mother and father in a loving and stable family, are the basis for the state's role in regulating marriage.
"It follows that any attempt to redefine marriage in such a way as to sever the link between the love of the partners in the marriage and the rights and needs of their children is a misuse of our state's power.
"Our government did not create the institution of marriage and they should not seek to dismantle it by altering its fundamental character."
Archbishop Costelloe, who succeeded Barry Hickey this year, had previously refused to be drawn publicly into the same-sex marriage debate. Archbishop Costelloe also took aim at critics of same-sex marriage opponents, saying accusations of homophobia were unfair because they were premised on the idea marriage should be open to anyone, which he said was wrong.
Last month, Federal MPs voted down legislation to change the marriage Act. A move in Tasmania to bring in State-based same-sex marriage was also defeated.
Labor MP and same-sex marriage supporter John Hyde said most Australians did not want religious organisations to determine what rights the law extended to all citizens.