Many New Hampshire towns will begin voting on a gay marriage resolution Tuesday.

About half of the state's towns have agreed to put a non-binding article on the ballot calling for a public vote on gay marriage. Other towns will take up the issue at their traditional meetings, many of which will be held this month.

New Hampshire became the fifth state to legalize gay marriage on January 1 when a gay marriage law approved by lawmakers went into effect. Fifty-four gay and lesbian couples married on the law's opening day.

Opponents of the law are calling for a public vote on the issue.

If approved, the resolution before town voters would urge state lawmakers to support placing a constitutional amendment defining marriage as a heterosexual union on the ballot, which, if approved, would effectively ban gay marriage and block the state's highest court from ruling in its favor.

The grassroots effort is being spearheaded by Representative David Bates, a Republican from Windham.

Last month, Democratic lawmakers killed two measures that attempted to reverse the law. House lawmakers passed on the marriage amendment and another bill that would have repealed the bill outright.