President Donald Trump’s decision to increase U.S. tariffs to 15 percent has drawn stark warnings from British business leaders who say the move risks hurting thousands of British exporters and slowing global economic growth.
In a social media post on Saturday, Trump said he would raise the existing 10 percent global tariff on countries to the “fully allowable” 15 percent “effective immediately.” The announcement followed a U.S. Supreme Court ruling that the president exceeded his authority by using emergency powers to impose tariffs on dozens of trading partners, including the United Kingdom.
The revised measure, introduced under alternative legislation, would increase tariffs on many British goods by a further 5 percentage points unless covered by existing exemptions.
The British Chambers of Commerce (BCC) said the change would affect around 40,000 British companies that export to the US.
William Bain, head of trade policy at the BCC, said: “We had feared that the President’s response to Plan B could be worse for British businesses, and this proves it. An additional 5 percent increase across a wide range of British exports would be bad for trade, bad for US consumers and would weaken global growth.”
He added that businesses on both sides of the Atlantic need clarity and stability and no further disruption.
The British government is holding high-level talks with Washington to maintain preferential arrangements under the UK-US Economic Prosperity Deal (EPD), announced by Trump and Keir Starmer in May last year.
Bridget Phillipson acknowledged the uncertainty facing exporters but insisted the UK expects its preferential trade arrangements to continue. “We want the best possible deal for British businesses,” she said.
The new 15 percent levy represents the maximum allowable under Section 122 of the U.S. Trade Act of 1974 and applies for up to 150 days. Economists estimate that the effective U.S. tariff rate could rise again to around 14.5 percent, reversing some of the cuts made in recent weeks.
Paul Ashworth, chief North American economist at Capital Economics, suggested revenue considerations may have influenced the decision, noting that higher tariffs lead to higher tariff revenues. He added that because Section 122 requires non-discriminatory application, countries such as the UK could potentially lose any preferential benefits previously secured.
The Supreme Court ruling has left billions of dollars in tariff revenue potentially in dispute and U.S. importers seeking refunds. Meanwhile, India has postponed a planned trade mission to Washington due to uncertainty over US trade policy.
Business groups warn that a new escalation of tariffs could hurt supply chains and investment decisions at a time when global growth is already fragile.
For UK exporters, particularly those outside the scope of the EPD, the immediate concern is a sudden increase in the cost of access to one of the UK’s largest overseas markets.
