New South Wales politicians behind proposed same sex marriage marriage laws for the state say they will push on with the bill despite the Federal Government's challenge to the ACT laws.

The Federal Government has announced plans to challenge the ACT's gay marriage laws in the High Court.

A group of New South Wales Liberal, National and Independent MPs plan on introducing the bill to state parliament before the end of the year.

Labor MLC Penny Sharpe says they are confident their bill will withstand any High Court challenge.

"The constitutional laws between the Commonwealth and the territories and the Commonwealth and the state are slightly different," she said.

"But we've had an inquiry into our bill and into the issues surrounding same sex marriage in New South Wales.

"We believe we can proceed and we're intending to do so.

"This is an issue that the community want, and that we are going to continue to proceed with."