The Supreme Court on Friday struck down President Donald Trump’s sweeping tariffs — a major repudiation of a core piece of Trump’s economic program.

The 6-3 decision is a rare instance of the conservative-led court reining in Trump’s expansive use of executive power. Chief Justice John Roberts and Justices Amy Coney Barrett and Neil Gorsuch joined the court’s three liberals in the majority.

“The President asserts the extraordinary power to unilaterally impose tariffs of unlimited amount, duration, and scope. In light of the breadth, history, and constitutional context of that asserted authority, he must identify clear congressional authorization to exercise it,” Roberts wrote, declaring that the 1977 law Trump cited to justify the import duties “falls short” of the Congressional approval that would be needed.

The ruling wipes out the 10 percent tariff Trump imposed on nearly every country in the world, as well as specific, higher tariffs on some of the top U.S. trading partners, including Canada, Mexico, China, the European Union, Japan and South Korea.

Several of those countries have entered trade agreements with the U.S. — and before the ruling indicated that they would continue to honor those agreements.

That is because the victory for the 12 Democratic-run states and small businesses that challenged Trump’s tariffs is expected to be short lived. The White House has signaled it will attempt to use other authorities to keep similar duties in place.

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It undercuts his ability to impose tariffs on a whim to address geopolitical conflict — like a threat to impose tariffs on countries that do business with Iran — and to threaten tariffs as he tries to gain a better negotiating position — like his tariff threats in an attempt to acquire Greenland. Businesses had decried those “national security” tariff threats for fueling economic uncertainty, but the administration said they were necessary for achieving its policy goals.

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The federal government could now be forced to issue billions of dollars in refunds to companies that paid the tariffs the high court ruled illegal. Many companies have already sued to protect their refund claims in the event the court struck down the Trump tariffs.