NEW YORK (Reuters) - Jury selection is expected to resume on Tuesday in U.S. Senator Robert Menendez's corruption trial, over what federal prosecutors called a years-long bribery scheme to help foreign governments, disrupt criminal cases and enrich himself.

Menendez, a Democrat and New Jersey's senior senator, has pleaded not guilty in Manhattan federal court to 16 criminal charges including bribery, fraud, acting as a foreign agent and obstruction.

Two New Jersey businessmen, Wael Hana and real estate developer Fred Daibes, are also defendants. A fourth defendant, Menendez's wife, Nadine, expects to be tried separately. All have also pleaded not guilty.

Jury selection began on Monday, and U.S. District Judge Sidney Stein told prospective jurors that the trial could last through June. Several dozen were excused from the case.

Menendez, a senator since 2006, has suggested he would try if acquitted to win a fourth full Senate term.

But recent polls of voters in Democratic-leaning New Jersey show overwhelming disapproval of Menendez's job performance, suggesting that any reelection bid would be a long shot.

Prosecutors have accused the Menendezes of accepting several hundred thousands dollars of cash and gold bars, as well as a Mercedes-Benz convertible, in exchange for Menendez's providing political favors, and aid to the governments of Egypt and Qatar.

FBI agents who searched the Menendezes' home in June 2022 found much of the cash hidden inside clothing, closets and a safe, prosecutors said.

Prosecutors accused Menendez of promising to help Egypt obtain arms sales and other military aid, and helping Hana obtain a lucrative monopoly on certifying halal meat exports to Egypt.

Menendez was also accused of trying to help Daibes obtain millions of dollars from a Qatari investment fund, and trying to disrupt a federal criminal case against Daibes in New Jersey.

A fifth defendant, Jose Uribe, pleaded guilty to bribery and fraud charges in March and agreed to cooperate with prosecutors.

REFUSING TO RESIGN

Menendez has resisted calls to resign from across the political spectrum, including from New Jersey Democratic Senator Cory Booker, but gave up leadership of the powerful Senate Foreign Relations Committee after his indictment.

Nadine Menendez's trial was separated from her husband's after her lawyers said she developed a serious medical condition that required a long recovery.

Her trial is now scheduled for July 8, and her husband's lawyers have suggested in court papers that if he testified in his own trial he may try to blame her.

The senator's lawyers are also awaiting a ruling from Stein on whether a psychiatrist can testify that Menendez routinely stored cash in his home because of a "fear of scarcity."

They said this was a response to the Cuban government's seizing his family's assets before he was born, and his father's suicide after Menendez stopped paying his gambling debts.

Menendez also went on trial in 2017 on charges he helped a wealthy Florida ophthalmologist in exchange for lavish gifts and political contributions. That case ended in a mistrial, and prosecutors did not retry him.

Democrats and independents who caucus with them hold a 51-49 Senate majority. Republicans hope in November's election to flip several seats in races that are expected to be close.

(Reporting by Jonathan Stempel in New York; Editing by David Gregorio)

By Jonathan Stempel