Noted televangelist Kenneth Copeland told his supporters that he believes Sen. Chuck Grassley, R.-Iowa, is violating the separation of church and state by asking a handful of large ministries to provide detailed spending reports to the Senate Finance Committee.

The Des Moines Register reported that Copeland, who is one of six televangelists to whom Grassley wrote inquiring letters in November of last year, made a concerned statement to Copeland supporters.

“The enemy is not going to steal what the Lord has won through this ministry, and he is not going to use this attack to bring harm to the rest of the churches and ministries in America,” Copeland wrote in a February statement.

The Rev. Creflo Dollar, who is featured in an Atlanta-based television ministry with his wife and has also been questioned by Grassley, also spoke out against the letters. Church Solutions details the senator’s probe in the March issue.

Grassley and the committee believe that because televangelists file as tax-exempt, nonprofit organizations, they must explain their unusually high expenses and revenue. In Copeland’s case, Grassley asked for his wife and him to submit information about compensation from the ministries, loans, gifts, use of private jets, housing allowances and costs, credit cards, vehicles, ownership of a ranch and more.

Though Copeland has partially complied with Grassley’s inquiry, submitting some of the requested documentation, the minister also replied with a 23-page letter from lawyers, arguing the constitutionality of the issue. Copeland argues that Grassley actually wrote the 1983 law that “protects churches from the IRS.”

Grassley’s camp has said that it will send follow up letters to Copeland and to three other televangelists who did not submit all they were asked to submit.

Copeland’s ministry is based in Newark, Texas.