First elected to the Senate in 2006, Menendez has become a liability to fellow Democrats, including New Jersey Senator Cory Booker, who joined a growing wave of politicians demanding his resignation.

Menendez was seen as a lock for re-election next year, but in light of the charges the typically blue state might give Republicans a shot at winning the seat and potential control of the Senate.

Menendez, his wife, and the businessmen are charged with conspiracy to commit bribery and conspiracy to commit honest services fraud. The senator and his wife are also charged with conspiracy to commit extortion under colour of official right. They face 20 years in prison on the most serious charge.

Two of the businessmen, Fred Daibes and Jose Uribe, pleaded not guilty as well. A third businessman, Wael Hana, entered a not guilty plea on Tuesday after he flew into New York from his native Egypt. The next hearing in the case is October 2.

All of the defendants declined to comment as they left the court with their lawyers.

The judge allowed all four defendants to sign personal recognisance bonds for their release. The senator’s is for US$100,000; his wife, for US$250,000; Uribe, for US$1 million; and Daibes, for US$2 million.

Menendez may travel outside the US on Senate business, but must surrender his personal passports. He cannot contact other witnesses besides his wife, the judge said.

Those charged with Menendez are Hana, 40, the owner of a New Jersey company with exclusive rights to inspect US halal meat exported into Egypt; Daibes, 66, a New Jersey developer and founder of Mariner’s Bank; and Uribe, 56, who works in the trucking and insurance business.

Federal agents raided Menendez’s home in June 2022 and found US$486,461 in cash stuffed in envelopes and hidden in clothes, wardrobes and a safe, according to the indictment. They also seized 13 gold bars valued at about US$82,000, as well as US$79,760 in cash from her safe deposit box, the US said.

On Monday, a defiant Menendez said at a news conference that the cash came from his personal savings account and not bribes, and he kept it for emergencies. He denied illegally helping Egypt, saying he has been tough on human rights abuses there.

When asked on Tuesday by reporters why he will not resign, Menendez replied: “Because I’m innocent. What’s wrong with you guys?”

By then, a growing number of Democratic senators, including Booker, had urged him to step down. He faces re-election in 2024, but has not said since his indictment whether he will run for another term.

Menendez previously went to trial in 2017 on corruption charges that he took gifts of private jet travel, a Paris holiday and campaign contributions in exchange for pushing a Florida doctor’s business interests within the US government. A judge declared a mistrial after jurors were deadlocked. The Justice Department dropped the case.

Prosecutors now allege the senator entered a plot with the others around the time the Justice Department dropped his first criminal case.

He is accused of giving Egyptian officials “highly sensitive” information about who worked at the US embassy in Cairo. He secretly wrote a letter that Egypt sent to his colleagues, urging them to lift a hold on US$300 million in US aid, prosecutors said. He had his wife tell Hana that he would approve a US$99 million arms sale to Egypt, according to prosecutors.

Menendez also pressured a US Department of Agriculture official to protect the exclusive right Egypt gave to Hana’s company, EG Halal Certified Inc., to certify US food exports as compliant with halal standards, prosecutors said.

They accused Menendez of seeking to influence a 2018 US indictment against Daibes over bank loans. In return, Daibes passed cash, gold bars and a recliner to Menendez and his wife, the US said. After returning from Egypt, Menendez did a web search on “how much is one kilo (2.2 pounds) of gold worth”, according to the indictment.

The senator also tried to interfere in the insurance fraud prosecution by New Jersey of an associate of Uribe, prosecutors said. In exchange, Uribe and Hana helped Menendez and his wife buy a US$60,000 Mercedes-Benz, according to the indictment.