Minnesota lawmakers on Saturday night approved a constitutional amendment banning gay marriage, sending it to voters for their approval, the Star-Tribune reported.

After roughly five hours of often emotional debate, House members voted 70 to 62 in favor of Republican Representative Steve Gottwalt's amendment, which seeks to define marriage as a heterosexual union in the Minnesota Constitution, thereby banning gay and lesbian couples from marrying. Minnesota currently bans such unions by law, but supporters say the law remains vulnerable to legal challenges without the amendment.

“This is not about hatred, it is not about discrimination or intolerance,” Gottwalt told House members, insisting his measure only asked voters to decide the issue.

“This allows the people of Minnesota to decide if the definition of marriage should be placed permanently in the state Constitution,” he said.

Republican Representative Tim Kelly urged lawmakers to reject the amendment: “If we put this amendment on the Constitution, we are taking a giant step backwards.”

Minnesota's upper chamber has already approved the amendment.

The House delayed an expected vote on Friday after an opening prayer by youth pastor Bradlee Dean, an opponent of gay rights, threw the chamber into disarray. Dean, who helms the ministry You Can Run But You Can't Hide International, suggested President Barack Obama and Democrats are not Christians. House Speaker Kurt Zellers said he was “offended at the presence of Bradlee Dean on the floor of the Minnesota House of Representatives.”

Earlier in the week, Democratic Governor Mark Dayton pledged to fight the effort with “every fiber of my being” and predicted voters would reject it at the ballot box.

“I think Minnesotans have much more compassion and understanding than they recognize and I think it will be defeated next year,” Dayton told reporters.

On Thursday, opponents of the measure released a compilation of sound bites from testimony heard on the amendment.