The largest federal workers’ union this week threw its support behind a Republican government funding bill, ratcheting up pressure on Democrats.

But many of the top labor unions told ABC News that they continue to back the strategy taken up by Democrats, breaking with the American Federation of Government Employees (AFGE), which represents hundreds of thousands of federal workers losing out on pay and staring down the threat of layoffs.

Many labor unions, a key bloc within the Democratic Party, support the push for an extension of Obamacare subsidies and remain eager to fight a president they view as an adversary of workers, some labor analysts and union officials said.

Jaime Contreras, an executive vice president at the 185,000-member Service Employees International Union Local 32BJ, said he sympathized with the challenges faced by federal workers but he disagreed with AFGE’s approach.

“They have to do what they have to do for their members,” Contreras told ABC News.

But, he added: “It’s a false choice in my opinion to say we need to give up affordable healthcare for millions and millions of Americans in order to bring federal workers back to work.”

SEIU 32BJ represents about 2,400 federal contractors who work as security officers, food-services workers and other employees, meaning they run the risk of missing out on backpay when the government reopens, Contreras said.

“These workers are bearing the brunt of this shutdown,” Contreras said, later adding: “We’re urging our Democratic friends to hold the line.”

The stay-the-course approach maintained by key labor organizations has likely eased the pressure faced by Democratic lawmakers in the aftermath of the AFGE announcement, some labor analysts told ABC News.

“The federal unions aren’t the biggest players,” Nelson Lichtenstein, a labor professor at the University of California, Santa Barbara, told ABC News.

AFL-CIO President Liz Shuler, who leads the nation’s largest labor federation, made up of unions representing nearly 15 million members, faulted President Donald Trump for what she considers an attempt to divide workers.

“As federal workers miss paychecks and line up at food banks, President Trump is more focused on pitting workers against each other than ending the shutdown,” Shuler told ABC News in a statement. “It’s time to fund the government, fix the health care crisis, and put working people first.”

Speaking at the White House on Thursday, Transportation Secretary Sean Duffy blamed Democrats for the impasse, saying while most workers might be able to miss one paycheck, “none of them can get through two paychecks.”

“If Democrats don’t get their act together very quickly, you’re going to see huge problems,” Duffy said.

The National Education Association (NEA), the nation’s biggest labor union representing almost 3 million members, stands by a statement earlier this month that supports addressing healthcare and government funding, an NEA official told ABC News.

United Steelworkers International President David McCall told ABC News he supports a solution “both prioritizing affordable health care and funding the essential services our government provides.”

The American Federation of State, County and Municipal Employees and the United Food and Commercial Workers referred ABC News to previous statements voicing similar sentiment.

“The Trump administration is putting huge, huge pressure on the federal unions,” John Logan, a professor of U.S. labor history at San Francisco State University, told ABC News. “Large parts of the rest of the labor movement are crying out for the Democrats to fight against the Trump administration and not give up.”

“Despite these cracks — which are understandable — the labor movement is fairly united in its position on the shutdown,” Logan added.

AFGE did not respond to ABC News’ request for comment.

The union drew headlines on Monday when its president, Everett Kelley, called for a “clean continuing resolution,” a position in line with Republicans who have declined to negotiate with Democrats over healthcare and other topics until after lawmakers vote to reopen the government.

“Both political parties have made their point, and still there is no clear end in sight,” Kelley said in a statement. “Today I’m making mine: it’s time to pass a clean continuing resolution and end this shutdown today.”

To be sure, at least one major union has sided with AFGE. Teamsters President Sean O’Brien has urged lawmakers to pass a clean continuing resolution, reiterating his position on Thursday in remarks made alongside top Trump administration officials at the White House.

“Do not put working people in the middle of a problem. They should not be in there,” said O’Brien, who last year became the first Teamsters union president to speak at a Republican National Convention.

The Teamsters did not respond to ABC News’ request for comment.

For his part, Trump on Thursday night called on Senate Republicans to eliminate the filibuster to pass the Republican funding bill and reopen the government.

“It is now time for the Republicans to play their ‘TRUMP CARD,’ and go for what is called the Nuclear Option — Get rid of the Filibuster, and get rid of it, NOW!” Trump posted.

The government shutdown, which entered its 30th day on Friday, appears unlikely to end anytime soon. Senate Democrats have voted 13 times to reject a Republican funding bill, and the upper chamber is out on recess until next week.