Anne-Marie Delahunt has called for a federal bill enshrining human rights after an ACT Human Rights Commission forum on the the next steps after marriage equality on Friday.

Ms Delahunt said it became clear during the debate over legalising same-sex marriage conservative politicians wanted to "institute religious rights at the expenses of the rights of individuals".

"I think that these issues, although they were lost in the parliament thank goodness, I am sure will be returned in the inquiry that Phillip Ruddock will be heading and I think that will provide an opportunity for the institutional power of the churches to increase their sway," Ms Delahunt said.

"That's what worries me a lot. The right of a school to discriminate against gay and lesbian teachers, surely that means in the school if there are young vulnerable kids they're going to be at risk because there's no sympathy and in fact antagonism towards them and I think that's a real concern."

The inquiry was announced to smooth the way for the passage of the Dean Smith bill before Christmas.

Mr Ruddock introduced the bill that changed the definition of marriage to be between a man and a woman in 2004 and opposes having a bill of rights.

But Ms Delahunt said having a human rights bill would make it clear having the right to freely practise religion did not give people a licence to discriminate according to their beliefs.

"I think what Tony Abbott and the others were hoping for was the right to express thier beliefs and bad luck about me. I'm an articulate, relatively wealthy woman who's able to stand up for myself. A 16-year-old person who's still questioning their identity doesn't have the same ability as me to fight back and that's what I'm really worried about," Ms Delahunt said.

"Many of the churches in Australia are extremely powerful and we're talking about groups of people who have been discriminated against and vulnerable all their lives. When I was younger I had quite a hard time. Not as hard as others but you know when Meg and I first got together I wasn't able to will her my super because you couldn't do that if you were gay.

"I have lived through all of that stuff and I don't want us to go back to a situation where I don't know if I can gain a service from an organisation because they're a religious based organisation and they just don't like lesbians."

Mr Ruddock will be assisted in the inquiry by Australian Human Rights Commission president Rosalind Croucher, Jesuit priest Frank Brennan and retired Federal Court judge Annabelle Bennett.

There are no terms of reference but the inquiry is due to report by March 31.