Supreme ruling throws US tariff programme into upheaval as UK warned it will be among worst hit
A supreme court ruling that outlawed most of the global tariffs the president introduced last year has set off a rapid legal and policy scramble, with US officials pausing collections, the Whitehall response warning that "nothing is off the table" and analysts saying the UK could be among the countries worst hit if a new 15% global levy goes ahead.
Supreme court decision and the legal basis for past tariffs
On Friday the US Supreme Court outlawed most of the global tariffs the president had announced last year, saying he had overstepped his powers. The ruling affected all tariffs that had been introduced using the International Emergency Economic Powers Act (IEEPA), including those announced on "Liberation Day" last year. In the immediate aftermath, the US administration said it would stop collecting tariffs the court ruled illegal and the US Customs and Border Protection agency said it would deactivate all tariff codes associated with IEEPA-related orders as of Tuesday at midnight.
Trump’s temporary 15% levy under Section 122 and its carve-outs
After the court ruling, the president initially proposed a 10% global tariff to replace those struck down and then revised the rate to 15% on Saturday. That 15% rate is to be introduced as a temporary solution under Section 122 of the 1974 Trade Act. Some products will be exempted from the levy, including critical minerals, metals and pharmaceuticals.
UK, EU and think-tank warnings over who loses out
Downing Street said no reciprocal action was "off the table" if the US does not honour its tariff deal with the UK, while adding that "no one wants a trade war. " The prime minister's official spokesman said the "majority" of the UK–US deal — such as the tariffs on cars, steel and pharma — was not expected to change, but described the situation as "evolving" and said discussions between the UK and US were ongoing. The EU put its US tariff deal on hold on Monday in response to the 15% announcement.
Analysis from the think tank Global Trade Alert found the UK will be among the countries worst hit if the 15% global tariff goes ahead because it had negotiated a 10% tariff deal with the US. GTA said countries such as China and Brazil, which currently have higher tariff rates, would be better off. The 15% global levy does not affect tariffs the UK and US had agreed on specific sectors — listed in context as steel, aluminium, pharmaceuticals, automobiles and aerospace — which represent most of the UK's trade with the US; only sectors beyond those already negotiated would face the 15% rate.
Business voices, US trade officials and market reactions
Andy Haldane, president of the British Chamber of Commerce, warned the UK would "sit towards the bottom of league table" of trade partners if the 15% global tariff came into effect and added: "The perversity of what happened of the weekend was that those who got good deals, the allies, have been most disadvantaged. "
Jamieson Greer, the US trade representative, said on Sunday that the administration was set to persist with its tariffs policy: "The policy hasn’t changed. The legal tools that implement that may change but the policy hasn’t changed, " and that the approach gives US business "a lot of leverage" in world trade. Greer also said he had spoken to the EU and other countries over the weekend and that "The deals were not premised on whether or not the emergency tariff litigation would rise or fall. "
Financial markets reacted as authorities moved to halt levy collections: the dollar slumped 0. 4% against a basket of other currencies, gold jumped 0. 6% to $5, 135 an ounce — its highest level since the end of January — while bitcoin fell as much as 4. 8% to $64, 300 before recovering to $65, 734. Futures tracking the US S&P 500 slipped 0. 5% on Monday morning.
Security incidents and other international fallout amid the trade upheaval
In a separate string of events this weekend, the Secret Service shot and killed an armed intruder who breached the perimeter of Mar-a-Lago early on Sunday. The president often spends weekends at the Palm Beach residence and private club, but he was at the White House during the incident, as was the first lady, Melania Trump. Ric Bradshaw, sheriff of Palm Beach County, said two Secret Service agents and one of his deputies were alerted that a person was within an inner perimeter. Bradshaw did not immediately identify the intruder; a news agency later identified the man killed as 21-year-old Austin Tucker Martin, citing a person familiar with the matter who spoke on condition of anonymity.
Mexico’s defence ministry confirmed one of the world's most wanted drug traffickers, the cartel boss known as "El Mencho, " had been killed by security forces. The operation in the western state of Jalisco on Sunday killed Nemesio Rubén Oseguera Cervantes along with at least six alleged accomplices, and set off a wave of violence with torched cars and gunmen blocking highways in more than half a dozen states. The ministry named him as co‑founder and leader of the Jalisco New Generation Cartel.
Domestically, an analysis of government records found that 77% of people who entered deportation proceedings for the first time in 2025 had no criminal conviction. And in New York, Mayor Zohran Mamdani ordered a citywide travel ban for all but emergency travel as the north‑eastern US was preparing for an intense winter storm.
