As federal funding for a two-track tunnel under the Hudson River hangs in the balance, Sens. Chuck Schumer and Cory Booker reaffirmed their support for the project on Monday morning, calling it President Donald Trump’s first test of his commitment to infrastructure.

Standing a block away from the Hudson River, the senators said they were calling on the president to put his money where his mouth is and advance what they called the most critical infrastructure project in the country.

“They didn’t invest enough in keeping the infrastructure going [at Penn Station],” Schumer said. “We want to reach across the aisle and work with the president and work with our Republican colleagues to build Gateway.”

The Gateway Program plans to overhaul the part of the Northeast Corridor running from Newark to New York, which has been slowly decaying over the past century. The Obama administration had been fierce supporters of the program, going as far as committing to pick up half of the tab. However, the Trump administration has only committed to considering providing funds.

On the morning of what has been promised to be a “summer of hell” of repairs on the Long Island Rail Road, Schumer warned of worse things to come if swift action isn’t taken to repair and upgrade the two-track rail under the Hudson.

“We do not want to repeat the mistakes of the past,” Schumer said. “If [the Hudson tunnels] fail, we will go into a recession immediately.”

Schumer also raised skepticism over the Department of Transportation’s decision to withdraw from the Gateway Program Development Corporation last week.

Flanked by members from the Ironworkers Local 580 Union, Booker added that construction of the additional tunnel would create union jobs at a critical time in the country.

“There’s no time in America more urgent than now for us to create good paying union jobs,” Booker said. “Studies have shown that a dollar invested in infrastructure in our country produces two dollars in increased economic output.”

Last week, the Federal Railroad Administration released a draft environmental impact statement estimating the Gateway Program would cost $12.9 billion — up from earlier estimates of $7.7 billion — which Schumer said was “worth every penny.”