Federal authorities are slow-walking $325 million in desperately needed aid for city public hospitals to cover coronavirus expenses, Sen. Chuck Schumer charges in a letter obtained by The Post.

“New York City has followed the steps outlined by FEMA, Congress has more than doubled the size of the Disaster Relief Fund, and yet the City still has not received the funding it so desperately needs,” wrote the Senate’s Democratic leader and veteran Brooklyn lawmaker. “This is must be fixed as soon as possible.”

President Trump first declared New York a major disaster to open up badly needed federal aid on March 20.

Congress then approved $45 billion to help local governments cover coronavirus costs like “emergency medical services, emergency sheltering, and emergency management operations costs,” the letter states.

Trump signed the new money into law on March 27 — and the city’s public hospital system, Health + Hospitals, submitted $650 million pandemic-related costs that same day.

The Federal Emergency Management Agency is supposed to pick up half the tab — $325 million — and cut the checks with all due haste. But after days of delays, City Hall reached out to Schumer to try and pry the money loose.

The money is critical as both New York City and New York State face massive budget crunches thanks to huge new pandemic-related costs — and a collapse in tax revenues due to the shutdown meant to contain the virus.

FEMA declined repeated requests to comment.

 Additional reporting by Steven Nelson in Washington