The Boy Scouts of America is expected to vote Wednesday on whether to lift its ban on gay members.
Scouts across the country say such a change would be huge—especially because churches sponsor 69 percent of all scout units.
The largest sponsors are the Church of Jesus Christ of Latter Day Saints, the United Methodist Church, the Catholic Church and Baptist churches.
So far, Catholic and Mormon leaders have withheld official comment on the proposed change. But Southern Baptist leaders have spoken against it.
Rev. Albert Mohler, president of the Southern Baptist Theological Seminary, recently blogged that the proposed policy "is almost sure to please no one and to lead to disaster for the scouts."
"Those pressing for a reversal of the national policy are not likely to be satisfied with a local option," he wrote. "They had demanded a national policy mandating the full inclusion of homosexuals throughout Scouting at every level.
"On the other side, those who wanted the current policy to remain in place will now have to reconsider any relationship with the Boy Scouts," Mohler added. "The scale of potential membership loss to the Boy Scouts of America is staggering."
Three religious liberty law firms have also warned that lifting the ban would jeopardize church-based troops that support the current policy.
In southeastern Virginia, churches sponsor 80 percent of the units in the Tidewater Council, and leaders say members are concerned.
"The BSA currently has about 3 million members and the 3 million members have been sold on membership standards as they have been for quite a long time," the Tidewater Council's Evan Sommerfeld said.
"And so all of a sudden we're running into a moment where there might be a national shift in those standards, so there are naturally a lot of people who are very concerned," he added.
Gay activists delivered over a million signatures to Boy Scout headquarters this week. But they say the proposed change—to allow local troops to decide whether or not to allow gays as members—does not go far enough.
The Human Rights Campaign says the scouts must adopt a nationwide policy to accept gays as both scouts and leaders.
What the Scouts decide this week could well affect membership, which is already in serious decline.
"At the moment, it's very noticeable that there are people sitting on the fence and they don't know that they want their families to personally invest in the program through membership because they want to know what the outcome of this decision is going to be," Sommerfeld said.
On Wednesday, those who oppose lifting a ban will hold a prayer vigil outside Boy Scout headquarters in Texas.
Meanwhile, both sides are urging their supporters to call headquarters Tuesday in a last-ditch effort to influence the scouts.