Washington, Dec 18 (AFP) President Donald Trump on Tuesday told the opposition Democrats' leader in Congress that impeachment is an attempted "coup" that is "subverting America's democracy."

In an extraordinarily angry letter stretching more than five pages, Trump told Nancy Pelosi, speaker of the House of Representatives, that "history will judge you harshly."

Referring to a famous miscarriage of justice in 17th century US history, Trump said he'd been given less rights than "those accused in the Salem Witch Trials."

The Democratic-led House is expected to impeach Trump for abuse of office in a vote on Wednesday. (AFP)

(This is an unedited and auto-generated story from Syndicated News feed, LatestLY Staff may not have modified or edited the content body)