WASHINGTON — House Democratic leader Nancy Pelosi on Thursday called on Democratic Representative John Conyers to resign, saying sexual harassment allegations against him were serious and credible, and that “zero tolerance means consequences for everyone.”

“The brave women who came forward are owed justice,” Pelosi told reporters. “Congressman Conyers should resign.”

Earlier on Thursday, an attorney for Conyers, 88, said the congressman, who returned to Detroit, Michigan, on Tuesday, had been hospitalized. He declined to provide details, but local media, citing a family spokesman, said his ailments were stress-related.

“Congressman John Conyers has taken ill and is currently hospitalized,” attorney Arnold Reed said on Twitter. Reed said he would release more details later on Thursday.

Conyers has already stepped down as the senior Democrat on the House Judiciary Committee, but he has resisted calls to resign from the House entirely. Reed told Reuters on Wednesday Conyers did not plan to resign.

Pelosi’s call for his resignation marked a shift. She had previously called for the House Ethics Committee to launch an investigation of the allegations, which it has done, but had stopped short of saying Conyers should step down.

Adding to the pressure, House Speaker Paul Ryan, the leading Republican in the chamber, also called for Conyers’ resignation. He referred to allegations detailed in a television interview on Thursday morning by a former Conyers’ staffer, Marion Brown.

Brown told NBC’s “Today” show that the congressman had “violated my body” and frequently propositioned her for sex.

“No one should have to go through something like that, let alone here in Congress, so yes I think he should resign. He should resign immediately,” said Ryan, who said he had just been briefed on allegations against Conyers.