Ohio Attorney General has filed the first major legal challenge to the $1.9 trillion COVID-19 relief package, dubbed as the American Rescue Plan, that US President Joe Biden recently signed into law, arguing its tax provision violates the state’s fiscal sovereignty.

Stimulus checks of up to $1,400 have already begun making their way to many of the millions of  workers and families as a crucial part of the plan, which also allocates billions of dollars to state and local governments for fighting the pandemic.

But in a 12-page filing against Treasury Secretary Janet Yellen, Ohio Attorney General Dave Yost challenged the provision which bars states from using the pandemic relief funds to offset tax cuts, and argued that the federal government was seeking to “commandeer” state taxing authority.

“Ohio seeks to enjoin federal officials from enforcing the unconstitutional Tax Mandate, and seeks declaratory relief establishing that the State of Ohio, under the Tenth Amendment to the US Constitution, retains the freedom to manage its own tax policy,” the lawsuit reads.

The lawsuit is the most serious legal salvo against the signature element of Biden’s economic agenda, and it follows a Tuesday letter by 21 state attorneys general — all Republicans — threatening to take action against it.

The filing notes that the American Rescue Plan includes a $195.3 billion aid program intended to help states recover from the pandemic-caused downturn. Yost said Ohio expects to receive $5.5 billion as its share of the program.

But in his suit Yost said Ohio would effectively be barred from implementing any plan such as a tax credit, deduction or rebate that “indirectly” offsets such funds.

“Thus, the Tax Mandate effectively prohibits reductions in taxes,” he wrote. “Any state that reduces taxes, and that experiences a loss in tax revenue, is subject to having billions of dollars in federal funding recouped by the Department of the Treasury.”

The case is reminiscent of challenges to the Affordable Care Act. The landmark health coverage law that became known as Obamacare faced dozens of Republican-led lawsuits, some of which continue to make their way through the courts 11 years after Obamacare became a federal statute.