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Last Updated Dec 12, 2017 4:14 PM EST

President Trump ignited a spat on Twitter Tuesday with Sen. Kirsten Gillibrand, a possible 2020 Democratic presidential contender, who called a day earlier for the president to resign over sexual harassment allegations.

Mr. Trump claimed that the New York senator used to come to his office “begging” for campaign donations and claimed she “would do anything for them.” It’s unclear what he meant by that remark.

Gillibrand fired back, asserting that Mr. Trump cannot silence her “or the millions of women who have gotten off the sidelines to speak out about the unfitness and shame” he has “brought to the Oval Office.”

On Monday, she called for the president to resign. She also led the charge last week in calling for the resignation of her colleague Sen. Al Franken, D-Minnesota, over sexual misconduct allegations.

A group of House Democratic women on Tuesday called for Congress to investigate the allegations that have been made against the president. A day earlier, three women called for a congressional probe, saying Mr. Trump needs to be held accountable for his actions in light of the growing “Me Too” movement.

White House Press Secretary Sarah Sanders, however, denied the sexual harassment allegations against Mr. Trump Monday. She said that there are eyewitnesses out there who can back up the president’s story.

Mr. Trump seemed to ruin that argument Tuesday morning when he claimed on Twitter that he either doesn’t know the women who have accused them or has never met them.

CBS News’ Emily Tillett and Jackie Alemany contributed to this report.

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