Libertarian Party presidential candidate Gary Johnson on Friday endorsed an effort to repeal Ohio's constitutional amendment defining marriage as a heterosexual union.

Voters in 2004 overwhelmingly approved the amendment. Freedom to Marry Ohio in May began collecting signatures to put the state's ban up for a vote next year.

At a campaign stop in Toledo, vice presidential nominee Judge Jim Gray urged voters to back the campaign.

“Unlike Mitt Romney or President Obama, Governor Johnson and I believe the right to marry who we choose is a constitutionally protected right,” Gray is quoted as saying in a statement released by Freedom to Marry Ohio. “”People of different faiths and different beliefs are free to follow those beliefs when it comes to embracing or opposing same-sex marriage within those faiths and beliefs. However, it should not be the purview of government to impose one set of beliefs over another. And government absolutely should not sanction discrimination against gay Americans who choose to marry.”

“Ohio’s Freedom to Marry amendment is an important step toward marriage equality in a key state. Governor Johnson and I are proud to lend our support, and urge the good people of Ohio to put their state on the side of equality and against government being in the business of deciding who can marry whom.”

(Related: Gay marriage could mean $165 million economic boost for Ohio.)