House Republicans will oppose a move by Democrats to allow former special counsel Robert Mueller’s own lawyer to testify as a witness during Wednesday’s hearing.

Rep. Doug Collins of Georgia, the top Republican on the House Judiciary Committee, said Chairman Jerry Nadler is considering allowing Aaron Zebley, counsel for Robert Mueller, “to testify as a witness alongside the former special counsel.”

Collins said such a move would potentially violate House rules.

“If true, the chairman’s unprecedented decision to allow a witness’s counsel to both advise him privately and simultaneously testify alongside him shows the lengths Democrats will go to protect a one-sided narrative from a thorough examination by committee Republicans,” Collins said in a statement.

Collins called the move to allow Zebley to testify, “a stunt.”

Zebley served as Mueller’s chief of staff during Mueller’s two year investigation into alleged collusion between Russians and the Trump 2016 campaign.

Mueller is slated to testify about the report before the Judiciary Committee for three hours on Wednesday. He’ll then appear as a witness before the House Intelligence Committee for two hours.

[Related: Pelosi may face new impeachment pressure with Mueller testimony]