One-third of all U.S. Democratic senators, including Senator Cory Booker, on Tuesday called on Senator Bob Menendez to resign after federal prosecutors charged him and his wife with taking bribes from three New Jersey businessmen.

Both Booker and Menendez represent the Northeastern state of New Jersey. Menendez, a Democrat, said on Monday that he would stay in the Senate and fight the charges.

Mendendez’s fellow Democrats in the Senate were largely silent when the criminal charges were unveiled on Friday. But in the days since, 17 senators have said he should step down.

Democrats narrowly control the chamber with 51 seats, including three independents who normally vote with them, to the Republicans’ 49.

“Stepping down is not an admission of guilt but an acknowledgment that holding public office often demands tremendous sacrifices at great personal cost,” Booker said in a statement. “I believe stepping down is best for those Senator Menendez has spent his life serving.”

Senate Democratic Leader Chuck Schumer has said Menendez has the right to a fair trial, but has not said whether he should stay or go. The White House has declined to say whether Menendez should step down.

Several Democratic elected officials in Menendez’s state of New Jersey, including Governor Phil Murphy, have also called for Menendez to resign. His New Jersey senate seat will be among those decided in next year’s election.

Democratic U.S. Representative Andy Kim has said he would challenge Menendez for his seat.

If the senator did resign, Murphy would appoint a temporary successor, and it would be unlikely to change the balance of power in the chamber.

Menendez’s legal troubles could complicate his party’s efforts to maintain control of the Senate, however, although New Jersey has not elected a Republican to the seat since 1972.

Menendez, 69, a powerful voice on foreign policy who has at times bucked his own party, has stepped down from his role as chairman of the Senate Foreign Relations Committee, as required under his party’s Senate rules.

Initially appointed by New Jersey’s governor to the seat, Menendez was first elected to the Senate in 2006 and served in the House of Representatives before that.

U.S. prosecutors said Menendez accepted gold bars and hundreds of thousands of dollars in cash in exchange for using his power and influence to aid the government of Egypt and interfere with law enforcement investigations into the businessmen.

If convicted, he and his wife, 56-year-old Nadine Menendez, could face up to 45 years in prison, though judges in these types of cases usually impose less than the maximum sentence.

Wael Hana, one of the businessmen charged with bribing Menendez, is scheduled to be arraigned in federal court in Manhattan at 2 p.m. EDT (1800 GMT) on Tuesday, prosecutors said.

The probe marks the third time Menendez has been under investigation by federal prosecutors. He has never been convicted.