Sen. Chuck Schumer caused a scene at a Manhattan restaurant when he began yelling at a wealthy and well-connected Donald Trump supporter that the POTUS is “a liar.”

Schumer, the top Senate Democrat, lost his cool on Sunday night at Upper East Side restaurant Sette Mezzo, according to witnesses.

He was dining with friends when he encountered Joseph A. Califano Jr. — the former US secretary of health, education and welfare under President Jimmy Carter and domestic policy adviser to President Lyndon B. Johnson — and his wife, Hilary, who were having a quiet dinner.

Onlookers said Schumer was incensed that Hilary — the daughter of William S. Paley, the founder and chairman of CBS — had voted for Trump, even though her husband, Joseph, is a well-known Democrat.

One witness said of the restaurant rant, “They are a highly respected couple, and Schumer made a scene, yelling, ‘She voted for Trump!’ The Califanos left the restaurant, but Schumer followed them outside.” On the sidewalk, Schumer carried on with his fantastical filibuster: “ ‘How could you vote for Trump? He’s a liar!’ He kept repeating, ‘He’s a liar!’ ”

Hilary confirmed the confrontation, telling Page Six, “Sen. Schumer was really rude . . . He’s our senator, and I don’t really like him. Yes, 1 voted for Trump. Schumer joined us outside and he told me Trump was a liar. I should have told him that Hillary Clinton was a liar, but I was so surprised I didn’t say anything.”

Joseph didn’t return calls for comment.

Another diner insists that Califano and his wife approached Sen. Schumer’s table. The diner said, “It was a pleasant conversation. Joe said the senator was doing a good job on health care. Joe joked that Hilary voted for Trump. The conversation continued outside because everyone left at the same time.”

A spokesman for Schumer said, “[He] and his wife ate at the café on Sunday, engaging in unremarkable conversation with patrons who approached their table. There were no heated exchanges with ‎anyone.”

Schumer has been making a lot of noise about Trump. On Monday he called for the  removal of Republican Representative Nunes as chairman of House Intelligence Committee. He’s also said he and the Democrats will attempt to filibuster Judge Neil Gorsuch’s nomination to the Supreme Court.