Gay activist questions govt decision

Opposing same-sex marriage is similar to supporting slavery or denying women the vote, a leading gay group says.

The ACT government has been forced to abandon plans to legally recognise same-sex civil union ceremonies after the Rudd government refused to support the move, upsetting the Australian Coalition for Equality.

"What's particularly disappointing is that the Rudd government refuses to give a proper explanation for its strident opposition to same-sex marriage except to say that traditionally marriage is between a man and a woman," spokesman Rodney Croome said.

"Well traditionally there was slavery and traditionally women didn't have the vote. But just because that was the tradition doesn't mean that change couldn't occur."

Mr Croome said slavery was abolished and women eventually achieved suffrage.

"Change did occur, we moved on from that," he said.

On Sunday, ACT Attorney-General Simon Corbell condemned the federal government's stance, accusing it of resorting to "undemocratic nineteenth century colonial style power" to override legislation which had the clear support of the majority of the ACT Legislative Assembly.

But the Rudd government has received support from the Australian Christian Lobby.

Managing director Jim Wallace says the federal government is right to intervene for moral reasons.

"Marriage is between a man and a woman," Mr Wallace told ABC Radio.

"It's not for two per cent of the population to redefine a majority institution, particularly when it's so important an institution to a healthy society."