WASHINGTON — U.S. Rep. Jamie Raskin on Sunday said he assumes former Vice President Mike Pence will voluntarily give testimony to the special committee investigating the Jan. 6 riot, but didn’t rule out a subpoena.

“He has a lot of relevant evidence, and I would hope he would come forward and testify about what happened,” the Maryland Democrat said on CBS’ “Face the Nation” on Sunday. “In no one’s case is a subpoena out of question, but I would assume he’s going to come forward and testify voluntarily, the way the vast majority of people have.”

Raskin led the impeachment of then-President Donald Trump in the aftermath of last year’s insurrection at the U.S. Capitol by Trump’s supporters.

Pence said last month in New Hampshire he would consider testifying if invited by the panel, and the panel’s top Republican, Liz Cheney of Wyoming, also said she hoped he would testify. Time is running out on the panel’s probe and on this Congress, however, with midterm elections in November.

The House committee already has heard from Pence’s former chief of staff Marc Short and former legal counsel Greg Jacob, and it has presented some of that testimony publicly.

Short said last week on “The Takeout” podcast that Pence has “profound concerns” regarding executive privilege with the prospect of revealing personal conversations with Trump, as well as concerns about partisanship on the committee.

“I don’t think any of those concerns have abated,” Short said, but added a formal invitation has yet to be issued. “I think he’s consistently said if we get that, then our lawyers and our team will duly consider it.”

Raskin also said he’d like to see former House Speaker Newt Gingrich and Ginni Thomas, the wife of Supreme Court Justice Clarence Thomas, voluntarily testify about what they know of the efforts to overturn the 2020 election results.

The committee has planned to release an interim report as soon as this month and its final findings by year-end.

That’s expected to included legislative proposals to fortify against future insurrection efforts. Raskin said Sunday a proposed bipartisan Senate rewrite of the Electoral Count Act is “a good first offer,” while saying he has a broader view of what needs to be done.

“We need to look far more systematically at what Donald Trump was trying to do,” he said. “This was a far more sweeping plot than just what happened in the last couple of hours there.”

The Senate bill, sponsored by Republican Senator Susan Collins of Maine and Democrat Joe Manchin of West Virginia, already has 10 Republican supporters needed to end a filibuster, though it’s not clear when it might come up for a vote. It would raise the thresholds in Congress for challenging electoral votes and clarify that the vice president doesn’t have the power to unilaterally reject electoral votes, among other changes.