NEW YORK — The Republican tax plan would seriously hurt both the transit system and the people who use it, according to a new report.

It would threaten federal funding the MTA relies on, a study from transportation advocacy groups Riders Alliance and the Tri-State Transportation Campaign found. The MTA gets about a quarter of its capital funding from the Federal Government.

"As if transit riders needed more bad news, it seems that Congressional Republicans are conspiring to make our commutes even worse," John Raskin, executive director of the Riders Alliance, said. "In a time when the American government is failing to do its job, responsible governments like New York State have to step up and find creative local funding sources to take care of basic tasks like running our subways and buses."

The Republican tax plan comes at a time when a state of emergency has been declared for the MTA. MTA Chairman Joe Lhota derided the tax bill, calling it "devastating" for New York and " particularly jarring" for the MTA.

"It will result in a reduction of federal funding for mass transit, will significantly impede the MTA’s access to the capital markets and will increase the tax burden for all of our customers," he said. "This legislation is not tax reform, it is tax deform and is a direct assault on all New Yorkers. The MTA’s subway and commuter rail networks are the circulatory system that allows the economy of the New York metropolitan area to function. Unfortunately, the Tax Bill will provide unnecessary ‘plaque’ that will clog the system."

It will specifically impact transit in five ways, according to the report:

Squeeze the budget with $1.5 trillion in federal tax cuts threatening key programs the MTA relies on Bring back corporate profits held offshore without setting any aside for infrastructure investment Slash the state and local tax deduction, which would put pressure on revenue sources that support public transit Eliminate advance refunding bonds, which the MTA has used to lower interest payments on its debt End the tax deduction for businesses that subsidize their employees’ transit fares

New York's transit crisis is more likely to worsen than it is to improve if the taxing plan goes forward and a new source of revenue isn't found, according to the report. Both organizations suggested congestion pricing.

“The Republican tax bill is a land mine of unintended consequences, and one of the groups that will feel its impact is transit users," Nick Sifuentes, executive director of the Tri-State Transportation Campaign, said. "As the federal government rolls back its support for public transit, states will have to step up to fill the breach—and congestion pricing is one of the best ways Governor Cuomo can ensure our subways and buses keep moving and our economy stays strong."