Former special counsel Robert Mueller will be joined in his testimony in front of the House Judiciary and Intelligence Committees tomorrow by Aaron Zebley, his chief of staff during his nearly two-year investigation.

Zebley is also the former lawyer for the controversial IT aide to Hillary Clinton who set up her private email server and smashed some of her mobile devices with a hammer.

“Aaron Zebley was the Deputy Special Counsel and had day-to-day oversight of the investigations conducted by the Office,” a spokesman for the special counsel’s office said Tuesday afternoon. “He will accompany Special Counsel Mueller to the Wednesday hearings, as was discussed with the committees more than a week ago.”

While there were conflicting reports about whether Zebley would end up serving as a witness alongside Mueller or if he’d be there as just as Mueller’s lawyer during the hearing, but Rep. Adam Schiff, the chairman of the House Intelligence Committee, made it sound like Zebley would appear in both capacities.

“We would like to make sure that to the degree he participates, that it may be on technical issues or other matters,” the California Democrat said this evening. “We don’t want him as a substitute for Mueller’s voice.”

Prior to joining Mueller’s investigation, Zebley worked with Mueller at the WilmerHale law firm following a career at the FBI which included two stints at the bureau, first as a Special Agent of the FBI in the Counterterrorism Division for seven years and next as Mueller’s chief of staff when he served as FBI Director. Zebley was also an assistant U.S. Attorney in Virginia.

But it was his time in private practice which originally drew the ire of Republicans when he joined Mueller’s special counsel investigation in 2017, because Zebley spent 2015 and 2016 representing Justin Cooper, a former Clinton Foundation adviser and IT aide who set up and maintained Clinton’s improper private email system for years while Clinton served as Secretary of State. FBI records even show that Cooper was involved in the destruction of some of Clinton’s personal devices.

“Cooper did recall two instances where he destroyed Clinton’s old mobile devices by breaking them in half or hitting them with a hammer,” FBI records say.

The move to have Zebley potentially testify alongside Mueller was widely condemned by Republicans as a political stunt.

Rep. Doug Collins of Georgia, the ranking Republican on the House Judiciary Committee, said that if Judiciary Chairman Jerry Nadler, D-New York, allowed this to happen, it might violate the rules of the House.

“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.

Congressman Jim Jordan of Ohio, a harsh critic of Mueller, echoed those sentiments as well.

“Rumor is that Aaron Zebley (Mueller’s Chief of Staff) will be on the witness panel with Mueller,” Jordan tweeted in response to these revelations. “You don’t get to change the rules right before kickoff, especially after a 22 month, $30 million investigation.”

Zebley served as Mueller’s right hand during Mueller’s two-year investigation into alleged collusion between the Russian government and members of the Trump campaign.

Mueller concluded that the Russians interfered in the 2016 election, but he did not establish any criminal conspiracy or coordination between the Kremlin and any associates of Trump or any other Americans. Mueller did not reach a conclusion on obstruction of justice, but Attorney General William Barr and Deputy Attorney General Rod Rosenstein concluded that obstruction did not occur.