Amtrak is warning of reduced or suspended services if a Republican-backed plan in Washington becomes law.

The railroad says a budget bill approved by a GOP-led House committee this week would cut its federal funding next year by nearly two-thirds – roughly $1.6 billion – to a level not seen in 20 years.

The busy Northeast Corridor in particular would see a roughly $1 billion reduction, according to a Democratic aide. Advocates warn the impacts would stretch to other lines, including in upstate New York.

The plan, which some New York Republicans are raising concerns about, would also potentially derail major modernization projects.

Sean Jeans-Gail, vice president of the Rail Passengers Association, says the spending proposal would send Amtrak into “survival mode.”

“I don't think House appropriators really gamed out the scenario,” Jeans-Gail said. “You get back to this situation where we're deferring maintenance, deferring upgrades. And that results in more disruptions, more breakdowns, more halted trains.”

The bill comes amid an ongoing squabble inside the House GOP caucus, with some of the more conservative members demanding sharp spending reductions next year, including at Amtrak, which they argue is overfunded.

Several Republicans from New York are pushing back on the plan from their own party.

Long Island Rep. Andrew Garbarino called himself “concerned” in a statement, saying, “​​I and other New Yorkers in Congress are actively engaging in discussions with Appropriations staff and Members on the topic.”

In his own statement, Suffolk County Rep. Nick LaLota invoked the state and local tax deduction, saying, “I will not be a part of another attempt to screw New York. I am looking forward to a lively amendment process to right some of these wrongs.”

A spokesperson for Staten Island Rep. Nicole Malliotakis indicated she is going through the bill and will submit amendments “wherever possible” to prevent cuts to “essential Amtrak operations.”

The Senate, meanwhile, is working on its own budget bill, which includes funding for Amtrak operations more on par with spending for the current year.

With budget season now in high gear, Democratic Rep. Adriano Espaillat, who blasted the House committee’s plan as an example of an “extreme MAGA philosophy," said he is counting on the Democrat-led upper chamber to hold the line.

“We must protect that corridor. We’ve got to revolutionize it, make it modern, make it resilient,” he said.

Asked about the proposed cuts, a spokesperson for Rep. Elise Stefanik, who chairs the House Republican conference, noted there will be “a significant amendment process” on the House floor.

Her team did not respond by publication to a question clarifying if the congresswoman would like to specifically see Amtrak spending amended as part of that process.

Stefanik has been outspoken in promoting operation of Amtrak’s Adirondack line, with her team saying she has supported Amtrak funding “throughout her time in Congress.”