A multibillion-dollar dispute between the Environmental Protection Agency and several nonprofit organizations escalated Saturday when one group sued the EPA and Citibank, seeking access to grant money that has been frozen under President Donald Trump.

Climate United contends that the EPA and Citibank have illegally withheld an award of nearly $7 billion announced last April. Citibank has housed the funds as part of a program to finance projects that address climate change.

The funds are part of a larger pot of money, $20 billion, that has been swept up in controversy after EPA Administrator Lee Zeldin called the green financing program a “scheme” that was “purposely designed to obligate all of the money in a rush job with reduced oversight.”

Now some of the nonprofits say that their bank accounts are frozen and that they are struggling to pay staff members.

Climate United had planned to loan the money to developers across the country for solar power, electric trucks and energy-efficient affordable housing projects, and said the freeze has meant small businesses and developers are unable to draw funds.

“We’re not trying to make a political statement here,” Beth Bafford, CEO of Climate United, said. “This is about math for homeowners, for truck drivers, for public schools — we know that accessing clean energy saves them money that they can use on far more important things.”

The EPA did not immediately respond to a request for comment.

“We have received and are currently reviewing the suit,” Citibank said in a statement. “As we’ve said previously, Citi has been working with the federal government in its efforts to address government officials’ concerns regarding this federal grant program.

Climate United is one of eight nonprofits that collectively received $20 billion from the Greenhouse Gas Reduction Fund, also known as “green bank” funding, during the Biden administration.

The money was appropriated through the 2022 Inflation Reduction Act and had been held in recipients’ accounts at Citibank since late last year. The nonprofits have been unable to make withdrawals for more than two weeks.

The funds were frozen after Zeldin issued a statement linking the grants to a hidden-camera video released in the final weeks of the Biden administration by Project Veritas, a conservative group known for using covert recordings to embarrass its political opponents.

In the video, Brent Efron, then an EPA employee, likens the agency’s efforts to spend federal money on climate change programs before leaving office to throwing “gold bars” off the Titanic.

A lawyer for Efron said his client was not referring to the Greenhouse Gas Reduction Fund.

Zeldin has called for Citibank to return the grant funding to the EPA and suggested potential fraud. The Department of Justice and the FBI subsequently launched investigations. Denise Cheung, a top federal prosecutor in Washington, D.C., resigned after determining that there was not enough evidence to order the funds frozen.