Washington CNN  — 

One of the nation’s leading Catholic civil rights groups is calling for House Speaker Paul Ryan’s chief of staff to resign after he allegedly made anti-Catholic comments to the House chaplain in April.

Catholic League president Bill Donohue referenced in a statement remarks the Rev. Pat Conroy made in a letter rescinding his resignation.

He alleged Ryan’s chief of staff, Jonathan Burks, told him the House wanted a chaplain who wasn’t Catholic.

“In his letter rescinding his resignation as House Chaplain, Father Patrick J. Conroy (Ryan has reinstated him) said that it was Burks who told him, ‘Maybe it’s time that we had a chaplain that wasn’t Catholic,’” Donohue said in the statement Friday. “It’s time Ryan found himself a new chief of staff. Anti-Catholic bigotry cannot be tolerated anywhere, and certainly not in Washington.”

AshLee Strong, spokesperson for Ryan, denied there was a Catholic bias in the office.

“To suggest there is any anti-Catholic bias in the speaker’s office is not only wrong, but absurd,” she said in a statement to CNN.

Ryan himself is also Catholic.

Donohue was referencing the letter from Conroy on Thursday, which said, “On Friday, April 13, 2018 your Chief of Staff, Jonathon Burks, came to me and informed me that you were asking for my letter of resignation. I inquired as to whether or not it was ‘for cause,’ and Mr. Burks mentioned dismissively something like, ‘maybe it’s time that we had a Chaplain that wasn’t a Catholic.’”

The letter continued: “At that point, I thought that I had little choice but to resign, as my assumption was that you had the absolute prerogative and authority to end my term as House chaplain.”

Burks disputed what Conroy wrote in a statement Thursday.

“I strongly disagree with Father Conroy’s recollection of our conversation,” he said. “I am disappointed by the misunderstanding, but wish him the best as he continues to serve the House.”

CNN’s Sunlen Serfaty contributed to this report.