CLEVELAND (RNS) Hundreds of United Methodists are meeting in Huron, Ohio, this week in an uphill bid to make their 12 million-member denomination more gay-friendly.

Activists are gearing up for next year's General Conference meeting in Tampa, Fla., where they plan to fight once again to change the church's official position that homosexual activity is a sin.

Unlike other mainline Protestant denominations in the United States that have moved to allow openly gay clergy and bless same-sex unions, United Methodists prohibit sexually active gay clergy and blessing same-sex unions.

"The practice of homosexuality is incompatible to Christian teaching," reads a section in the Methodists' Book of Discipline.

But the nearly 700 people expected to attend the four-day conference at Sawmill Creek Resort that opened Thursday (Aug. 25) are hoping the 2012 General Conference will be different than recent assemblies, where they saw repeated defeats.

"We might not get everything we want, but we'll get some of it," said the Rev. Troy Plummer of Chicago, an organizer of the Huron conference. 

"I think something dramatic will happen in Tampa. The vote will be close, by just a handful of votes this time. We're about to make it happen."

Previous conference votes showed the movement prevailing in the United States but failing in Europe and Africa, said Plummer, noting that delegates from fast-growing overseas conferences tend to be more conservative.

"We have the votes in the U.S.," he said. "Now we're working to get the votes worldwide."

The Ohio meeting comes at the same time as some 2,000 evangelical Presbyterians gather in Minneapolis for a two-session on their future within the Presbyterian Church (USA), which now allows both gay clergy and same-sex unions.

United Methodists number about 8 million in the United States. The other 4 million are mostly in Europe, Africa and the Philippines. The Rev. Ken Chalker, pastor of University Circle United Methodist Church in Cleveland, said a vote by Ohio Methodists to allow openly gay clergy would lose by a substantial margin.

"I don't know what tea leaves he's reading," said Chalker, referring to Plummer. "The rules on ordaining gays or blessing same-sex couples are not going to change in Tampa. It would be wonderful if there were changes. I certainly would support them."

But the Rev. Chet Harris, pastor of the Dueber United Methodist Church in Canton, would not. He believes homosexuality is a sin, on the same level as adultery and sex outside of marriage.

Harris said the push within the church for approval of same-sex relationships could be gaining ground and should be taken seriously. "The movement is strong," he said. "These people are sharp. They wouldn't be doing this unless they thought they could pull off a coup."

Harris predicted that if the gay-friendly movement prevails, there would be a mass exodus of United Methodists, including himself.

"I will not serve in a church that will ordain homosexuals," he said. "I will not serve in a church that affirms their lifestyle. If this thing goes the distance -- and I think it has the potential -- it will splinter us like bamboo."