WASHINGTON >> Rep. Nancy Pelosi, the House Democratic leader, moved swiftly today against the House’s longest serving lawmaker, calling for the House Ethics Committee to investigate sexual harassment charges against Rep. John Conyers Jr., the top Democrat on the House Judiciary Committee.

Conyers, 88, who has represented parts of the Detroit area in the House since 1965, confirmed the settlement of a wrongful termination complaint in 2015 from a staff member who had accused him of sexual harassment. But he denied that the staff member was fired for refusing to have sex with him. The settlement was first reported by BuzzFeed News on Monday.

Pelosi and senior Democrats on the Judiciary Committee offered little support, and the Ethics Committee said it had indeed opened an investigation.

“Any credible allegation of sexual harassment must be investigated by the Ethics Committee,” Pelosi said, adding that there should be “zero tolerance for harassment, discrimination, bullying or abuse in the House.”

Sexual harassment charges are roiling Capitol Hill, as they have shaken Hollywood, Silicon Valley and the media. But in Conyers’ case, the charges quickly meshed with other issues, from the advanced age of some House members to the desire of younger Democrats for new leadership.

Specifically, the House Judiciary Committee would become a focal point for inquiries into the conduct of President Donald Trump and his administration if Democrats seize control of the House in the 2018 midterm elections. And some Democrats have been angling for stronger leadership.

Conyers, who has for decades led the Democrats on the Judiciary Committee, denied any wrongdoing and said the money paid to his accuser amounted to a “reasonable severance payment.”

But legal documents published by BuzzFeed show repeated allegations by women staff members of requests for sex, suggestive touching, caresses and other sexual improprieties.

The calls for an investigation came as Democrats raised the prospect that Conyers would at least be asked to step aside from the top Judiciary post. A founding member of the Congressional Black Caucus, Conyers holds the venerated title of Dean of the House. But he has also been a target of Democrats who are eager to bring fresh blood into the Judiciary Committee leadership for some time.