WASHINGTON >> Sen. Bob Menendez came under heavy pressure to resign today as a surging number of his Democratic colleagues in the Senate, including fellow New Jersey Democrat Cory Booker, urged him to step aside over the federal bribery allegations against him.

More than 20 Senate Democrats have now said that Menendez should resign, including several Democrats running for reelection next year. Calls for his resignation came in quick succession after Booker’s statement, including from the head of the Senate Democrats’ campaign arm, Michigan Sen. Gary Peters. Menendez has refused to leave office but has not yet said whether he will run for reelection next year.

Menendez, the longtime chairman and top Democrat on the powerful Senate Foreign Relations Committee, and his wife Nadine are accused in an indictment released Friday of using his position to aid the authoritarian government of Egypt and to pressure federal prosecutors to drop a case against a friend, among other allegations of corruption. The three-count indictment says they were paid bribes — gold bars, a luxury car and cash — by three New Jersey businessmen in exchange for the corrupt acts.

In his statement, Booker said that while Menendez deserves the presumption of innocence, senators should adhere to a higher standard, and the details of the allegations against Menendez have “shaken to the core” the faith and trust of his constituents. He said the indictment of Menendez includes “shocking allegations of corruption and specific, disturbing details of wrongdoing.”

“As senators, we operate in the public trust,” Booker said. “That trust is essential to our ability to do our work and perform our duties for our constituents.”

Menendez has denied any wrongdoing, saying he merely performed as any senator would and that the nearly half million dollars in cash found in his home — including some stuffed in pockets of clothing — was from personal savings and kept at hand for emergencies. Authorities recovered about 10 cash-filled envelopes that had the fingerprints of one of the other defendants in the case on them, according to the indictment.

Menendez, along with his wife and two of the businessmen co-defendants, are to be arraigned Wednesday.

Another defendant, Wael Hana, was arrested at New York’s Kennedy airport today after returning voluntarily from Egypt to face the charges. According to the indictment, Hana served as a conduit to Menendez for Egyptian military and intelligence officials, passing messages to and from the senator and arranging meetings.

Menendez’s defiance in recent days is similar to his insistence that he was innocent after he first faced federal bribery charges eight years ago — a case that ended with a deadlocked jury in 2017. As he did then, he is stepping down from his leadership position on the Foreign Relations panel, as per Senate Democratic caucus rules. But he has otherwise made clear that he’s not going anywhere.

“I recognize this will be the biggest fight yet, but as I have stated throughout this whole process, I firmly believe that when all the facts are presented, not only will I be exonerated, but I still will be New Jersey’s senior senator,” Menendez said on Monday at Hudson County Community College’s campus in Union City, where he grew up.

The calls for his resignation are in sharp contrast, though, to his first case. And Booker’s call is especially significant in the clubby Senate, where home state colleagues tend to stay away from public criticism of each other. Booker and Republican Sen. Lindsey Graham of South Carolina, testified as character witnesses in Menendez’s last trial.

The increasing Democratic calls for Menendez to resign put increased pressure on Senate Majority Leader Chuck Schumer and other Democratic leaders who have so far stopped short of recommending that Menendez step down. Schumer has not commented on the indictment since saying in a statement on Friday that Menendez would step down from the Foreign Relations panel.

The White House also declined to weigh in. Press secretary Karine Jean-Pierre told reporters aboard Air Force One that “the senator did the right thing by standing down from his chairmanship.” She did not say whether President Joe Biden believed he should resign from his seat, nor would she comment on how his presence would affect public faith in the Senate.

“That is for Senate leadership to speak to, that’s for Sen. Menendez to speak to,” she said.

Democratic senators calling for Menendez to step down on Monday and today included Tammy Baldwin of Wisconsin, Jon Tester of Montana, Jacky Rosen of Nevada, Bob Casey of Pennsylvania, Michael Bennet of Colorado, Mark Kelly of Arizona, Mazie Hirono of Hawaii, Martin Heinrich of New Mexico, Amy Klobuchar of Minnesota, Raphael Warnock of Georgia, Kirsten Gillibrand of New York, Sen. Chris Murphy of Connecticut, Maggie Hassan of New Hampshire and Elizabeth Warren and Ed Markey of Massachusetts.

Democratic Sens. John Fetterman of Pennsylvania, Peter Welch of Vermont and Sherrod Brown of Ohio all called for his resignation over the weekend. The number of calls from the Senate Democratic caucus was expected to grow.

If Menendez does run for reelection, he will face at least one challenger in a primary: Democratic Rep. Andy Kim announced over the weekend that he will run for the Senate because of the charges against the state’s senior senator.

And Menendez would likely be running without the support of his party. Peters, who urged his resignation today, is the chairman of the Democratic Senatorial Campaign Committee, which provides campaign support to incumbent Democratic senators and challengers.

Peters said in a statement Monday evening that Menendez is not able to serve effectively. “As elected officials, the public entrusts us to serve in their best interests and in the best interests of our country,” Peters said.

In court today, a judge ordered Hana freed pending trial on $300,000 cash bail and a $5 million bond.

Hana’s lawyer, Lawrence Lustberg, said after the hearing that his client is innocent and has a long friendship with Nadine Menendez that predated her marriage to the senator by years. “He has pleaded not guilty because he is not guilty,” Lustberg said.

Prosecutors say Hana gave the senator’s wife, Nadine Menendez, a “low-show or no-show job,” paid $23,000 toward her home mortgage, wrote $30,000 checks to her consulting company, promised her envelopes of cash, sent her exercise equipment and bought some of the gold bars that were found in the couple’s home.

Hana also sought the senator’s help in fending off criticism from U.S. agricultural officials after Egyptian officials gave his company a lucrative monopoly over certifying that imported meat met religious standards, the indictment said.