The Presbyterian Church has just become the largest Protestant group to formally recognize and approve of gay marriage.

Church leadership approved redefining marriage in its constitution on Tuesday that would allow a “commitment between two people,” a move that the General Assembly endorsed last year but had not yet receive approval from a majority of the 171 regional districts of the denomination, according to a New York Post report.

The Presbytery of the Palisades in New Jersey was the 86th “yes” vote for the measure, getting it the required majority approval.

The change is set to officially take effect June 21 and will affect 1.8 million members from 10,000 congregations.

A total of 41 presbyteries have rejected such a redefinition, even though the provision doesn’t force clergy to preside over a gay marriage ceremony. An additional presbytery had a tie vote.

The church has allowed its ministers to conduct gay weddings if it happened in states that had allowed the practice and local church leaders signed off on it.

The move has had consequences for church membership. About 428 of the churches who had been a member of hte denomination abandoned it for a more conservative denomination, or dissolved entirely, according to the report.

Not surprisingly, the move has harsh critics within the Presbyterian faith. Carmen Fowler LaBerge, who is president of the conservative Presbyterian Lay Committee, said according to the report that the redefinition was “an express repudiation of the Bible,” and asked Presbyterians to protest the decision by sending their donations elsewhere.

The Presbyterian Church is the largest, but not the first Protestant denomination to back gay marriage: back in 2005, the United Church of Christ approved it for its 1.1 million members.

The Episcopal Church elected the first openly gay Anglican bishop back in 2003. The church doesn’t have a formal position on gay marriage but allows bishops to decide for their own churches.

The Evangelical Lutheran Church in America dropped barries to gay ordination in 2009, and also leaves the decision to individual congregations.