Speaker Nancy Pelosi says the House would move to impeach Donald Trump over his role in inciting this week’s violence if he did not resign ”immediately.”

In a letter to members of the House, she invoked the resignation of Richard Nixon amid the Watergate scandal, when Republicans prevailed upon the president to step down and avoid the humiliation of an impeachment, calling Trump’s actions a ”horrific assault on our democracy.”

Three House Democrats are planning to introduce articles of impeachment Monday, meaning the chamber could potentially vote on his removal from office by mid-week, just a week before President-elect Joe Biden’s inauguration.

Trump says he won’t attend, making him the first incumbent since Andrew Johnson in 1869 to skip his successor’s swearing-in ceremony.

Vice-President Mike Pence is expected to attend the inauguration.