Rep. Justin Amash (I-MI) said on Sunday that House Speaker Nancy Pelosi (D-CA) is “making a mistake” by not starting impeachment proceedings against President Donald Trump.

Amash, who recently left the Republican Party to become an independent, told CNN reporter Jake Tapper that Pelosi’s reluctance to begin impeachment proceedings is a “big problem.”

“From a principled, moral position, she’s making a mistake,” Amash said. “From a strategic position, she’s making a mistake.”

“When she says things like, ‘Oh, I think that we need to have the strongest case before we go forward,’ what she’s telling the American people is she doesn’t think there’s a strong case,” he continued. “If she doesn’t think that, then she shouldn’t open her mouth in the first place and say she thinks there’s impeachable conduct.”

The Michigan congressman pointed out that most Americans don’t have time to read special counsel Robert Mueller’s 448-page report in full.

“They expect Congress to do the work for them. They want Speaker Pelosi to do the work,” Amash said. “They want other members to do the work and if she doesn’t want to go forward then we have a big problem.”

Before he left the party, Amash was the only Republican in Congress who called for Trump’s impeachment after the Mueller report was released.

Watch Amash below: