Twenty five states sued President Donald Trump's administration on Monday over a wave of tariffs against dozens of countries.
The US says the tariffs, which range between 10% and 12.5%, were imposed due to trading partners - including the UK, China and the European Union - failing to properly tackle forced labour.
In a legal document seen by the BBC, the coalition of Democratic states said the decision was “arbitrary, capricious, and contrary to law.”
In response, White House spokesman Kush Desai said the US is "using its lawful authority" to address practices that burden American businesses.
Desai added that any foreign countries failing to deal with the importation of goods produced with forced labour was "unreasonable" and must be addressed.
The new tariffs, which came into effect in July, were imposed under Section 301 of the 1974 US Trade Act, legislation which is designed to target nations that use forced labour.
The duties cover 99.4% of US imports, according to the Office of the US Trade Representative (USTR).
During Trump's first term, he used Section 301 to impose trade tariffs on China and they survived challenges in court.
Desai added: “Section 301 tariffs have proven to be a legally durable tool since the president's first term, and they remain so now.”
The lawsuit said the Trump administration “cannot use forced labour as a pretext to continue its illegal tariff scheme.”
"The tariffs the USTR imposed are so broad that they defy the USTR's own stated aims and make a mockery of the statute used to justify them," it said.
"President Trump's illegal tariffs are nothing more than a tax on hardworking families," said New York Governor Kathy Hochul.
In a statement, Oregon attorney general Dan Rayfield said: "Despite losing every step of the way, Trump is trying yet again to inflict more chaos on working families and homegrown Oregon businesses.
"We're all paying the price for these unlawful tariffs, not foreign governments," he added.
Several of the affected trading partners have expressed disappointment over the new tariffs, with Brazil and Japan's governments separately calling the measures "unjustified".
China's foreign ministry spokesperson Mao Ning described the tariffs as an "excuse for political manipulation". Washington and Beijing have been locked in a tit-for-tat tariffs war which is currently on hold.
Some analysts have also questioned how countries would be able to show that they had properly addressed the forced labour claims.
The lawsuit will pose a "formidable challenge" to Trump's levies, Alex Capri, a business lecturer at the National University of Singapore told the BBC.
There is also a lack of credible evidence to back claims that countries have harmed US firms by violating forced labour rules, he said.
Capri added that he expects "carve outs and walk-backs to gradually take the bite out of these tariffs".
The legal action marks the latest move surrounding a slew of trade policies unveiled by Trump since he returned to office in January 2025.
Many of the wide-ranging duties Trump imposed on global trading partners in his so-called "Liberation Day" tariffs in April last year were struck down by the US Supreme Court.
"The Supreme Court has made it clear that this administration cannot ignore the law to impose sweeping tariffs," Hochul said.
The court's decision prompted tens of billions of dollars in refunds to companies that had paid the levies.
The president has long argued that tariffs protect American workers and boost the US economy.
The tariffs that were struck down were replaced by a temporary 10% levy on all global imports. Those tariffs expired in July.
More tariffs could also be on the horizon as the US is currently investigating 16 countries over claims of manufacturing overcapacity.
Source: BBC
– Agencies
