A day after the first legally recognised same-sex civil ceremony in Canberra, Senator Fielding spoke out against allowing gay couples to wed.

''A bloke cannot marry his brother; it is not right,'' he said. ''A woman cannot marry their sister; it is not right. A bloke cannot marry a bloke because it is not right, and a female cannot marry a female because it is not right. I don't support this.''

Labor senator Joe Ludwig reiterated the Rudd Government's stance that gay relationships should be recognised across the nation in civil partnership schemes and not with marriage.

But Greens leader Bob Brown said the Government was made up of ''undemocratic wowsers'' and ''sad sacks'' who wanted to override the Australian Capital Territory laws allowing gay couples to hold a ceremony to create their legal relationship.

He said Labor's reluctance to embrace gay marriage was a ''Howardian hangover''.

''Why on earth in 2009 can't this Labor Government remove discrimination from people who care to love each other and want to engage in the same rights to publicly celebrating that connection that everybody else in the community has?'' he said.

''It is just Howardian hangover by Rudd Labor. It is offensive, it is hurtful and it is destructive.''

Federal Attorney-General Robert McClelland this week asked the ACT Government to amend its civil partnerships ceremonies scheme, and it agreed yesterday.

After strong advocacy from the Australian Christian Lobby, Mr McClelland sought changes meaning same-sex ceremonies would remain but they would have little legal effect.

After the ACT Government said it would adopt the changes, he indicated the Commonwealth would not seek to quash an amended scheme. But many gay activists were unhappy at the changes. Activist Corey Irlam said: ''The critical difference between the ceremonies originally sought by the ACT and those allowed by the Federal Government is that the latter have little legal effect, leaving the formal declaration of a civil partnership in the hands of the Registrar of Births, Deaths and Marriages and not in the hands of civil partnership celebrants.

''It is a step forward that Prime Minister Rudd has backed off from a veto, but the system the ACT Government has now accepted is still essentially a paper process without legally binding ceremonies.''