The ACT's same-sex marriage law will take centre stage in the High Court today as the Commonwealth mounts a challenge to overturn the legislation, reports the ABC.
The first weddings under the law have been planned for next weekend, but the future of the law will be in doubt until the High Court rules.
The Commonwealth brought on its challenge almost as soon as the ACT law was passed, saying it is inconsistent with the Federal Marriage Act which defines marriage as between a man and a woman.
Professor George Williams says the case could go either way. 'The Commonwealth has a strong argument with covering the whole field of marriage,' he said.
'But on the other hand the ACT also has a strong argument that the Self-Government Act gives them room to move.
'Ultimately it will be a question of whether the ACT same-sex marriage law is inconsistent with the Federal Marriage Act.'