The United Methodist Church shot down a plan that would have opened the door to gay marriage in the church on Tuesday, a blow to theological liberals that exposes the rift within the third-largest Christian denomination in the U.S.

At the Methodists’ General Conference in St. Louis, conservative delegates soundly defeated the One Church Plan, which would have allowed some churches to celebrate same-sex weddings and ordain lesbian, gay, bisexual and transgender clergy while permitting other churches not to do so. Church officials had pushed the plan as the best way to keep the denomination together.

Instead, delegates at the convention approved the Traditional Plan, which keeps in place rules that prohibit same-sex marriage and the ordination of LGBT clergy. In addition, it adds measures to crack down on clergy members who disobey those rules.

The vote left liberal members of the church openly debating their options on Tuesday evening. Some who have called the United Methodist Church home their entire lives were considering leaving the denomination.

“I’m truly gutted,” said Rev. Mandy McDow, the pastor of Los Angeles First United Methodist Church and a supporter of LGBT rights, who was at the conference. “If there’s the possibility of rebuilding, I can stay…. I can’t remain in an institution built on oppression.”