President-elect Donald Trump’s promise of dramatic downsizing of the federal government could have a direct impact on tens of thousands of federal workers who live in New England.

On Tuesday, Trump announced that he is appointing Tesla CEO Elon Musk and former presidential candidate Vivek Ramaswamy to head what he’s calling a “Department of Government Efficiency,” which aims to “dismantle government bureaucracy, slash excess regulations, cut wasteful expenditures and restructure federal agencies.”

The Project 2025 policy manual proposed by a host of conservative organizations and Trump advisors suggests dramatic changes in federal civil service rules to give the president far more leeway to hire and fire government employees. It also suggested getting rid of unions for government employees.

At the end of his previous presidential term, Trump issued an executive order that allowed the president to recategorize thousands of career civil servants into political appointees, meaning they could be fired and replaced. President Joe Biden promptly reversed that order when he took office. Presumably, Trump will reinstate it.

A September report from the Congressional Research Service, the internal research arm of the U.S. Congress, said that there are more than 60,000 federal employees in New England, based on partial tallies provided by the White House. About half of that total lives in Massachusetts.

Those numbers do not include postal workers, federal court employees, members of the military, or law enforcement personnel, like those who work for the FBI. A more expansive estimate compiled by the Census Bureau suggests that as many as 120,000 people in the region describe themselves as federal government workers.

For all of these government workers, the next few months will be full of uncertainty.

“The threats that have been coming out of the political sphere have said they might fire us all,” said Lilly Simmons, who heads the union representing 400 workers in the Environmental Protection Agency’s New England office in Boston. “They might close our entire office. We’re going to fight every way we can.”

The EPA employees are working under an existing four-year contract, she said.

“The current administration is abiding by our contract,” Simmons said. “That’s it. We worry about today. And in January, on January 20th — you probably have a few months before everything goes to, you know, pick your expletive.”

Simmons said her unit is coordinating with others in the labor movement and other allies, particularly members of Congress, to prepare to protect the EPA employees’ work.

“We’re still living through a climate emergency,” she said, “and we’re doing everything we can to reduce the damaging effects.”

Mike Gayzagian, president of AFGE Local 2617, which represents around 2,000 Transportation Security Administration employees in New England, said his members face a unique risk because they are not covered by federal civil service law. TSA workers instead are covered by an administrative agreement that can be changed at any time.

“They can come in literally and just change their minds on how we’re structured,” Gayzagian told GBH News. “And, you know, with the stroke of a pen, do pretty much whatever they want. … It’s almost like a private company.”

Gayzagian said his members aren’t protected simply because of the function they serve. Before the creation of TSA, airport security was handled by private firms. A new administration could try to return to that model.

“Depending on who the secretary of Homeland Security is … if they if they put somebody in place who says, ‘You know what, we don’t want the union here anymore,' there’s a good chance that the union could just be taken out of TSA,” he said.

But like Simmons, Gayzagian cautions that at this point everything is just speculation.

“Nobody really knows what’s going to happen until the new administration tips their hand and says, 'OK, this is how it’s going to go,'” he said. His union is trying to get information from TSA management, but with a transition coming, those people in management today may not be around several weeks from now.

That’s one more reason it’s hard for the thousands of federal employees to prepare.

“Essentially, we have to prepare for the worst and hope for the best,” Gayzagian said.