Sen. Kamala Harris (Calif.) became the first Senate Democrat to call for Parnas to testify, telling MSNBC that the accusations levied by Parnas “should be pursued and should be reviewed” by the Senate.

“I think he should be brought before us so that we can determine his credibility. There are many ways to judge credibility,” Harris said.

Sen. Ed Markey (D-Mass.) endorsed that effort, saying Parnas should be added to Democrats’ list of impeachment witnesses.

“Mitch McConnell cannot be allowed to cover up the truth and protect Donald Trump. The Senate must hear directly from John Bolton, Mick Mulvaney, and Lev Parnas,” Markey tweeted.