Premier Mike Baird has offered support for a motion passed in the NSW lower house saying MPs should be free to express their views on same-sex marriage and wishing the Federal Parliament well on debate over the issue.

The move on Wednesday by the Coalition-dominated chamber comes as Prime Minister Tony Abbott, a friend of Mr Baird's, faces pressure to grant his party a free vote on marriage equality in the federal parliament.

Independent MP Alex Greenwich. Credit:Wolter Peeters

Independent Sydney MP Alex Greenwich, who is openly gay, put up a priority motion noting NSW MPs and the community hold various views on the issue of marriage equality, and wishing their federal colleagues "a respectful debate that is tolerant of all views".

The motion, which was unanimously supported, noted "the importance of MPs being free to express their own view and the views of their electorates on this issue".