British businesses are facing renewed uncertainty following the US Supreme Court’s dramatic intervention on tariffs, with companies left unsure whether to plan for a 10% tariff, higher rates, or further legal reversals.

“We’ve spent the last year adapting to one set of rules, and now the goalposts have moved again,” said Rain Newton-Smith, director general of the CBI. “What businesses need above all is stability and predictability.”

UK exports to the US — worth approximately £60 billion annually — had already been disrupted by earlier tariff rounds, with sectors including automotive, steel, and whisky particularly affected.

The government said it was “engaging at all levels” with the Trump administration to secure the best possible terms for British exporters, but declined to comment on the prospect of a UK-US trade deal.

Small and medium-sized businesses reported the greatest impact, with many lacking the resources and expertise to navigate rapidly changing trade regulations across multiple jurisdictions.