MILWAUKEE - A growing number of pastors in the United Methodist Church say they are no longer willing to obey a church rule that prohibits them from officiating at same-sex marriages, despite the potential threat of being disciplined or dismissed from the church.

In some parts of the US, Methodist pastors have been marrying same-sex couples or conducting blessing ceremonies for same-sex unions for years with little fanfare and no backlash from the denomination. Calls to overturn the rule have become increasingly vocal in recent weeks, ratcheting up the pressure for the Methodist church to join other mainline Protestant denominations that have become more accepting of openly gay leaders.

While trials of pastors who conduct same-gender ceremonies have only occurred once every several years, the threat is indeed real. The Rev. Amy DeLong of Osceola in western Wisconsin faces a three-day trial starting Tuesday in Kaukauna on two charges: violating a church prohibition on the ordination of "self-avowed practicing homosexuals" and marrying a lesbian couple.

The jury for the church trial will be selected from a pool of Wisconsin United Methodist clergy. A total of 13 clergy will be chosen to serve during the trial and penalty phase.

DeLong said she told her supervisors years ago that she was in a lesbian relationship and felt comforted by the support and caring she received in response.

While she avoided discussing her relationship in local church settings, she said her efforts to live halfway in the closet and halfway out took such a toll that she finally decided to break her silence. She agreed to marry a lesbian couple in the fall of 2009, and she didn't mince words when she reported it in a required ministerial report a few months later. Eventually the two church charges were filed against her.

"I would be lying if I said this process hasn't been difficult, but I also feel called to break the silence and tell my own truth regardless of the consequences," said DeLong, 44. "When I entered (the ministry) I did not suspend my conscience. It's incumbent on me not to perpetuate its unjust laws."

The chances of getting the rule reversed within the Methodist church are far from certain, however. Rule changes must be approved by delegates at the church's General Conference, held every four years. Because a growing number of delegates come from Africa, the Philippines and other theologically conservative regions, voting patterns reflect strong resistance to change.

That hasn't stopped Methodist clergy in the US from raising the stakes. Hundreds of pastors from areas including Illinois, Minnesota, New York and the northeastern New England states have signed statements in recent weeks asserting their willingness to defy the rule.

Those who do so could be charged with violating denominational law and forced to face a church trial. Penalties could include defrocking or suspension from the ministry.

At a conference this month in Minnesota, the Rev. Bruce Robbins of the Hennepin Avenue United Methodist Church invited clergy to sign a statement saying they'd be willing to conduct any wedding, not just heterosexual ones. He said more than 70 signed it.

Robbins said he was driven to a sense of urgency because efforts are under way to have Minnesota's constitution limit civil marriages to heterosexual couples.

"One of the tragedies is, there are so many things we should be attending to: poverty issues, justice issues," he said. "I wish this didn't have to be at the center of our efforts today. But it is because of the inequality, the unfairness of the policy."

Similar efforts in New York this month drew signatures from more than 140 clergy and another 500 signatures of support from lay people, according to an organizer. Another 100 clergy did the same in New England, and at least a dozen there have actually conducted same-sex marriages with no complaints.