“This is an impeachable offense,” Painter said on MSNBC on Monday, referring to allegations that Trump pressured Ukraine to investigate former Vice President Joe Biden , a potential political rival in 2020.

Former White House ethics attorney Richard Painter is urging House Speaker Nancy Pelosi (D-Calif.) and the Democrats to begin impeachment proceedings against President Donald Trump .

Painter, who served as ethics chief in the White House of President George W. Bush, said Trump had “committed multiple high crimes and misdemeanors,” adding:

What is happening when the House refuses to impeach him is that he continues to do more and more of it. And that is what is happening. He is emboldened to continue to violate the Constitution.

“If Speaker Pelosi doesn’t have the courage to impeach him, he’s going to keep on doing it,” Painter added.

Painter predicted that Trump will claim during next year’s campaign that the lack of impeachment was “proof” he didn’t do anything wrong. He also urged the House to quickly vote on articles of impeachment.

“All of the evidence is already there. We don’t need more to impeach this president,” he said. “And if they don’t do it, I think the Democrats are going to lose in 2020 and probably deserve to lose.”

Later on Twitter, Painter said that Republicans will lose control over the Senate next year if they don’t vote to convict Trump.

“The evidence is OVERWHELMING,” he wrote.

See his full discussion on the MSNBC panel in the video above.