Opponents of Governor Andrew Cuomo's effort to legalize gay marriage in New York on Saturday held their first Mayday for Marriage! rally.

The statewide bus tour made its first public stop in downtown Elmira, located in the south-central part of the state.

The conservative group New Yorker's Family Research Foundation is behind the campaign to douse Cuomo's plan to make New York the sixth state in the nation to legalize the institution.

“In same-sex marriage relationships we're intentionally denying children a mom or a dad,” Rev. Jason McGuire told attendees, NBC affiliate WETM reported. “That's just not right and just not good public policy. We want to encourage marriage between a man and a woman.”

McGuire likened passage of marriage equality to the 1973 Supreme Court decision Roe v. Wade.

“My generation asks the last, 'Where were you when they tried to redefine when life began?' The next generation will ask of ours, 'Where were you when they tried to redefine marriage? ' What will we say to future generations?”

Four additional clergy also spoke at the tour's inaugural stop: Rev. Duane Motley of New Yorkers for Constitutional Freedoms, Rev. Bern Lytle of the Big Flats Wesleyan Church in Big Flats, Rev. David Hackett of the Christian Hope Center in Corning and Rev. John McConnell of the Southside Alliance Church in Elmira.

Elmira City Mayor John Tonello said he disagreed with the group's message: “I'm hopeful it passes the state Legislature this year and gay marriage is approved.”

A majority (58%) of New York voters support altering the state's marriage laws to include gay and lesbian couples. But passage in the state Senate, where a similar measure died in 2009, remains uncertain. Senator Ruben Diaz Sr., the most outspoken opponent of the legislation in the Senate, will headline a May 15 rally in the Bronx.

Lawmakers in Rhode Island recently announced they'll move ahead with a civil unions bill, angering gay marriage supporters who have vowed to fight on.