The workers, two thirds of whom are older than 50, say the AFL-CIO offered them a new contract in September that included a three-year pay freeze, less reliable hours, cuts to sick leave and weaker seniority rights.

After they rejected those terms, the AFL-CIO notified them Monday it would impose the contract.

“It’s absolutely hypocritical,” said Jessica Maiorca, spokeswoman for OPEIU Local 2 in Silver Spring, Md. “How do we expect people to take us seriously when we’re not providing employees the benefits we think our union members need?”

The workers have not set a date for a strike.

The AFL-CIO is one of the most visible names in the labor movement with more than 55 affiliated unions and 12 million international members, including factory workers, bakers, teachers, roofers, police officers and flight attendants.

The union body said it would keep negotiating with its office employees, who make an average salary of $60,000 — higher than typical administrative roles in the U.S.

“We are involved in negotiations with our administrative staff and while we hope to avoid any work stoppages, we fully respect their rights through this process,” spokesman Josh Goldstein said in a statement. “However, we will not negotiate publicly and the critical work of the labor movement continues uninterrupted.”

This isn’t the AFL-CIO’s first tangle with its workers.

Roughly 300 employees at its headquarters in the District refused to cross a picket line in 1986 after 12 food services workers there went on strike for higher wages.

Analysts say a high-profile walkout could deal a public relations blow to AFL-CIO President Richard Trumka, who recently accused “greedy corporations” of hogging their corporate tax-cut windfalls.

“This campaign is about holding corporations and politicians accountable to their claims and getting a much-needed raise for America’s workers,” Trumka said while unveiling the union’s joint push with the Communications Workers of America for pay bumps in December.

Working while his own employees are on strike — including the people who drive him and clean his office, according to the OPEIU — would be seen as “taboo,” said Joseph Slater, a labor professor at the University of Toledo College of Law.

“It’s embarrassing for people in leadership to be seen doing that,” he said.

But the AFL-CIO and the labor movement, in general, he added, is navigating rough financial straits.

Union membership nationwide has declined in recent decades, and the Supreme Court decision in June to free public workers from paying mandatory dues to unions that represent them (Janus v. AFSCME) is expected to further strangle funding.

About a third of the AFL-CIO’s members work in the public sector.

“They are going to have a lot less money coming in,” Slater said.

Almost three quarters of the AFL-CIO employees considering a walkout have worked there for at least a decade, said Maiorca, the union representative, while 54 percent have been at the organization for longer than 15 years.

The AFL-CIO’s internal tussle over pay and other benefits comes as employers nationwide appear hesitant to dole out major raises, even as the economy surges.

The country’s jobless rate hit 3.7 percent in September, the lowest point since 1969, but pay has barely budged as the labor market keeps tightening. Annual pay for the typical worker has climbed just 2.8 percent in the past year, despite the intensifying competition for workers.

Economists aren’t sure why wage growth hasn’t returned to the healthier levels of before the Great Recession. Some blame the proliferation of low-paying jobs, such as service roles, as positions in manufacturing that came with heftier checks declined. Others have pointed to the fading power of unions.

An estimated 14.8 million workers belonged to unions in 2017, according to the Bureau of Labor Statistics, compared to 17.7 million in 1983.