Markets rallied after President Donald Trump reacted to the Supreme Court’s major ruling on tariffs.

High-level talks are ongoing after Donald Trump’s announcement of 15% global tariffs and the Government wants “the best possible deal” for UK firms, a Cabinet minister has said.

Trade attorneys said the volume of cases seeking refunds for tariffs already imposed – more than 1,800 already – could surge now that the justices rejected the legal rationale behind an estimated $175...