IRS Commissioner John Koskinen will not testify at a House Judiciary Committee hearing to examine his alleged misconduct as some Republicans make the case for his impeachment.

The IRS said in a statement Monday that Koskinen appreciates the request to speak at Tuesday’s hearing but did not have time to adequately prepare.

“When the committee announced this hearing, he was returning from China after meeting with tax administrators of 43 nations. The committee’s quick timetable left him without the time to fully prepare for Tuesday’s hearing,” the agency said. “In addition, he also has been preparing for a previous commitment to appear before a House Ways and Means Committee hearing on Wednesday.”

“Koskinen believes there is an extensive record from the congressional investigations and previous hearings on the actions taken at the IRS,” the agency added.

The IRS said that Koskinen will provide written testimony, and an agency spokesman added that Koskinen has told the committee that he will be willing to appear before the panel in the future.

Koskinen had been invited to speak at Tuesday’s hearing, which will center on the findings of the House Oversight and Government Reform Committee’s investigation into him. Many committee members have accused Koskinen of failing to comply with a subpoena and making false statements under oath during Congress’s investigation into the IRS political-targeting scandal.

Oversight Committee Chairman Jason Chaffetz (R-Utah) and committee member Ron DeSantis (R-Fla.) are slated to testify, as well as an unidentified Democratic witness. Chaffetz introduced a resolution to impeach Koskinen last fall and another resolution to censure him last week.

The Judiciary Committee will hold a second hearing in June during which outside experts will discuss the Oversight Committee’s findings and make recommendations about any further congressional action.

Updated at 12:41 p.m.