New Jersey Governor Phil Murphy threw up another potential hurdle to block Manhattan traffic-congestion pricing with an inquiry into the potential revenue hit to the Port Authority of New York and New Jersey.

The plan would cut bridge and tunnel toll collections “without a commensurate increase in revenue from an alternative source,” Murphy wrote to Port Authority Executive Director Richard Cotton in an Oct. 11 letter obtained by Bloomberg News.

“I want to be clear that any reduction in the Port Authority capital plan because of congestion pricing should not come at the expense of any New Jersey projects,” wrote the governor, a 65-year-old Democrat and retired Goldman Sachs Group Inc. senior director who won a second term last November.

Tom Pietrykoski, a Port Authority spokesman, said in an email that such an analysis “is already underway” and its results will be reported to the governor.

The letter is Murphy’s latest attempt to quash a plan to raise about $1 billion annually for the Metropolitan Transportation Authority — or at least delay it. In a letter to U.S. Transportation Secretary Pete Buttigieg last month, Murphy said the plan should be subject to a full environmental impact study, a step that could take years. The governor last month repeated the request to President Joe Biden.

Murphy says he supports mass transit to combat climate change, but that New Jerseyans who choose to drive shouldn’t pay both the crossing toll and the traffic charge.

Drivers from New Jersey, who now pay $13.75 at peak at Hudson River crossings operated by the Port Authority, would hand over as much as $23 more for congestion access if they have an E-ZPass. Different rates would apply for vehicles without an E-ZPass. For drivers traveling from Princeton, New Jersey, to the Manhattan district, the average round trip auto cost would be $120 with the additional toll, according to an August environmental assessment report.

The plan should be delayed, he says, at least until the New York City area has improved mass transit. Two new Hudson River rail tunnels won’t be ready until 2035, and a Port Authority midtown bus terminal has a 2031 completion date.

The Port Authority collects a $13.75 peak toll from every passenger car that enters Manhattan from New Jersey via the George Washington Bridge and the Holland and Lincoln tunnels.

In the letter, Murphy asked Cotton for impact estimates on annual revenue and a “worst-case scenario” for 15 years of capital improvements. The authority has a $2.7 billion capital spending plan for 2022 on assets that include bridges and tunnels; air, ocean and bus terminals; the World Trade Center; and a commuter train line.

“The MTA’s plan is essentially a revenue transfer from the Port Authority to the MTA,” Murphy wrote. “The MTA’s plan is the unilateral action of a New York transportation authority designed to raise revenue for New York projects that will impact the capital planning of a bi-state entity’s ability to deploy funding that would benefit both states and the region.”