A group of more than 600 United Methodist clergy and church members are bringing church law charges against Attorney General Jeff Sessions over the Trump administration's "zero tolerance" immigration crackdown — chiefly the policy that has separated thousands of children from their parents along the U.S.-Mexico border.

The group accuses Sessions, a fellow United Methodist, of violating Paragraph 270.3 of the denomination's Book of Discipline. He is charged under church law with child abuse, immorality, racial discrimination and "dissemination of doctrines contrary to the standards of doctrine of the United Methodist Church."

In a letter addressed to Session's pastors, 640 clergy members and laity urge "some degree of accountability" for the top law enforcement official in the country, who they say is affiliated with United Methodist churches in Alabama and the suburbs of Washington.

"We write to you ... in the hopes that you will, as members of our connectional system, dig deeply into Mr. Sessions' advocacy and actions that have led to harm against thousands of vulnerable humans," the signees wrote in the letter.

"As members of the United Methodist Church, we deeply hope for a reconciling process that will help this longtime member of our connection step back from his harmful actions and work to repair the damage he is currently causing to immigrants, particularly children and families."

A spokesman for the Justice Department declined to comment on the complaint.

Meanwhile, Pope Francis also criticized the policy, telling Reuters that he supported the U.S. Catholic bishops who have joined other religious leading in condemning the separation of parents and children as "immoral."

"It's not easy, but populism is not the solution," Francis said.

He added that populists were "creating psychosis" on the issue of immigration and said without immigrants, Europe would "become empty."

Not all evangelical Christians oppose Trump's policy. Pastor Bill Sutton, of McAllen, Texas, told NBC News that his faith tells him to support the president.

"I don't believe any person is in any office that God has not allowed it to be there," Sutton said. "I do care about these kids. I just don't know what to do. But I've got to put my trust somewhere. I can't solve it, so I'm trying to believe that the government will do that which is right."

And Mike Jones, an evangelical Christian from North Carolina, said he questions whether the harrowing images of kids held in detention centers are even real.

"I think it's all a big lie," Jones told NBC News. "I don't think that that's happening."

The two churches to which Sessions is said to belong — Ashland Place United Methodist Church in Mobile, Alabama, and the Clarendon United Methodist Church in Alexandria, Virginia — did not immediately respond to phone calls from NBC News.

The signees of the letter also criticized Sessions for invoking Romans 13, a Bible verse, to justify the Trump administration policy of breaking up children and parents at the border. They said the "misuse" of that line from Scripture was in "stark contrast to disciplinary commitments to supporting freedom of conscience and resistance to unjust laws."

The contents of the letter were first reported by the United Methodist News Service.

The Rev. William Lawrence, an authority on Methodist history and practices, said that anyone in the church can bring a charge against anyone else, whether clergy or layperson — but that a formal complaint outlining specific charges is rare.

Lawrence said the church's Book of Discipline allows, "in the most extreme circumstances," for a church-led trial and even the expulsion of a lay member. But the first step, he said, would be for the respondent to resolve the issue through "pastoral conversations" with his pastor and district superintendent.

"In the 50 years of the United Methodist Church as a denomination, I am not aware of any case that moved beyond those initial stages," Lawrence said.