The Senate is close to finally having privately run restaurants, ending decades of in-house cafeterias whose large deficits have cost the chamber millions of dollars.

A month ago, that long-awaited change seemed in peril. A bill necessary for the switchover stalled in the Senate, and the deadline for signing a contract with a private vendor was quickly approaching.

But on Tuesday the Senate unanimously passed the bill, which ensures certain benefits and job security for the 100 or so employees who now work in the cafeterias. It has to be signed into law before the Architect of the Capitol can sign a contract with Restaurant Associates, the company that already handles food service in the House.

House and Senate staffers said the bill should pass the House easily, and Restaurant Associates is expected to sign a contract in the upcoming weeks.

“We know of no objections to the restaurant bill and expect to move it through the House,” said Kyle Anderson, spokesman for the House Administration Committee.

Passing the Senate was the major obstacle, and now the main task is working out all the contract’s specifics, said Howard Gantman, Sen. Dianne Feinstein’s spokesman.

“We are very hopeful it will all go through,” he said, adding that the California Democrat is anxious to see it “moved as soon as possible” in the House.

Feinstein has lobbied hard to bring in a private company in her role as chairwoman of the Senate Rules and Administration Committee, which oversees the cafeteria’s management.

She sees privatization as a solution to the ongoing deficit of Senate Restaurants.

Last year, the cafeterias lost $1.37 million; this year, that number is expected to top $2 million, Gantman said. Feinstein wrote in a letter to Senators in early May that $250,000 will have to be taken from the chamber’s emergency fund just to cover payroll in July.

Bringing in Restaurant Associates will stem such losses, Gantman said. The House, which has had privately run cafeterias since 1986, hired Restaurant Associates in December. Since then, the company has remodeled the cafeterias and offered meals with local and sustainable food.

RA also has a contract with the upcoming Capitol Visitor Center, meaning that after its contract with the Senate, it would run nearly every restaurant in the Capitol complex.

The Senate is in store for a significant change. The Architect of the Capitol has run Senate Restaurants since 1961, and before that, the whole operation was under the Senate Rules and Administration Committee.

That in-house status meant an operation not unlike that of a local business, with unique recipes (such as the infamous Senate Bean Soup) and long-term employees. Many cafeteria employees have been there for decades, getting to know their Congressional clientele well.

That intimacy made switching to a private company somewhat difficult. Senators wanted to ensure employees weren’t left out in the cold, and some disagreed on the best way to do that.

Feinstein’s bill guarantees the same basic pay and benefits and offers a $25,000 buyout for those employees who retire. About half are expected to take it. But the bill almost met its demise when several Senators objected to it in early May because they thought the protections weren’t strong enough.

Democratic Sens. Edward Kennedy (Mass.), Barbara Mikulski (Md.), Sherrod Brown (Ohio) and Bob Menendez (N.J.) wrote Feinstein a letter asking that more protections be put in the bill, including assurances that the employees would be able to unionize.

“Whenever federal employees’ jobs are contracted out to the private sector, workers worry about basic issues like job security, wages, and the ability to unionize,” the Senators wrote in the letter. “We understand that Restaurant employees remain concerned about these issues in the privatization process.”

Feinstein responded that she was “dismayed” at the hold-up, and she warned Senators that food prices would go up 25 percent if cafeterias weren’t privatized.

But after some back-and-forth with the Senators and Restaurant Associates, everyone agreed to the legislation as originally written, Gantman said. Any remaining issues will be worked out in the contract, he said.

“There was a lot of back-and-forth about what is doable,” he said. In the end, he added, “we felt this was the best we could come up with.”

Gantman said all the specifics about a Senate switch aren’t yet set in stone, but the AOC and the committee may look into the same environmentally friendly efforts in place in the House. In House buildings, Restaurant Associates offers easy recycling and biodegradable utensils and cups.

If the contract is signed, RA will have four months to take over, putting the opening date at some point in the fall. The contract will also include a remodeling of the Dirksen cafeteria, Gantman said, much like the remodeling done recently in the House cafeterias.