Rep. Adam Schiff (D-CA), the top Democrat on the House Intelligence Committee, on Wednesday said that “you’d have to go back to Watergate” to find an investigation comparable to the ongoing probe into Russia’s interference in the 2016 election.

“Sen. Warner also says this is the most important investigation involving national security he’s ever gotten involved in all the years of public service,” CNN’s Wolf Blitzer said to Schiff, referring to remarks Senate Intelligence Committee Vice Chairman Mark Warner (D-VA) made at a press briefing earlier Wednesday. “Do you agree with him?”

“I do,” Schiff replied.

On Monday, Schiff called for Nunes to “recuse himself from any further involvement in the Russia investigation, as well as any involvement in oversight of matters pertaining to any incidental collection of the Trump transition.”

Schiff on Wednesday said that he can think of “two other investigations that are of equal seriousness” with respect to the United States’ “national interests.”

“Obviously the 9/11 Commission and the joint congressional investigation into 9/11 is in that category,” he said. “But you’d have to go back to Watergate to find something truly analogous.”