Jim Petro, a Republican and Ohio's former attorney general, on Monday endorsed an effort to repeal Ohio's 2004 voter-approved constitutional amendment which prevents the state from recognizing any relationship other than a heterosexual marriage.

Petro announced his support during a press conference in Columbus.

“Last year, my daughter Corbin married Jessica Gelman in Massachusetts, where same-gender marriages are legal,” Petro said in a statement. “They are expecting a child soon, and deserve the same protections guaranteed to other families. Seeing their happiness, and realizing all the rights they would be denied here in Ohio has proven to me the importance of equal marriage in our state.”

“I'm thoroughly convinced that bringing marriage equality to Ohio is the right thing to do. This amendment is rooted in a central conservative value, namely freedom – the freedom to love, the freedom of religion, and the freedom from big government. I am proud of to endorse this amendment.”

In March, Ohio Senator Rob Portman endorsed marriage equality in much the same way, crediting the coming out of his son Will for changing his position on the issue, though Portman has said that he does not plan to campaign in favor of changing Ohio's law.

The group FreedomOhio is collecting signatures to put the question on next year's ballot.

(Related: Phil Burress warns Ohio politicians against backing gay marriage.)