Just over a year ago, British Prime Minister Keir Starmer was quite chuffed.

After Donald Trump announced punishing tariffs on goods from America’s major trading partners, Starmer became the first to strike a deal with the U.S. president. In exchange for substantial new access to the U.K. market for American agricultural exports, Trump agreed to lower tariffs on British goods to 10 per cent, down from 25 per cent.