WASHINGTON, United States (AFP)—A United States (US) federal judge on Monday blocked President Donald Trump from imposing a $100,000 fee on employers filing visa applications for foreign highly-skilled workers.

District Judge Leo Sorokin ruled in a lawsuit filed by 20 Democratic-ruled states that the move usurped taxation powers held by Congress and the fee for the H-1B visas constituted an unlawful tax.

“The substance and application of the $100,000 payment reveal that it is a tax, regardless of what the payment is called,” Sorokin wrote in his 42-page ruling.

“The President had no power or delegated authority to impose a tax on H-1B petitions,” he wrote.

A different federal judge upheld the $100,000 fee in December in a separate case. That ruling is currently being appealed.

That lawsuit was brought by the US Chamber of Commerce, a pro-business lobbying group, and the Association of American Universities, which represents 69 US-based research schools.

Trump announced the new H-1B visa policy in September, arguing that the system was being abused to replace American workers with people willing to work for less money.

The H-1B fee is part of a larger immigration crackdown by the Republican president, who has unleashed a massive push against migrants since returning to the White House.

The United States awards 85,000 H-1B visas per year on a lottery system. India accounts for around three-quarters of the recipients.

H-1B visa fees previously cost up to $5,000.

Tech entrepreneurs — including Trump’s former ally Elon Musk — had warned against targeting H-1B visas, saying that the United States does not have enough homegrown talent to fill important tech sector job vacancies.