President Trump must not try to “interfere” with an investigation that has led to the indictment of a former aide by firing special counsel Robert Mueller, Senate Minority Leader Chuck Schumer warned Monday.

“The president must not, under any circumstances, interfere with the special counsel’s work in any way,” Schumer, a New York Democrat, said Monday. “If he does so, Congress must respond swiftly, unequivocally, and in a bipartisan way to ensure that the investigation continues.”