Donald Trump and Keir Starmer at the White House in February.Keir Starmer has been urged to form “a united front” with the European Union and Canada against Donald Trump as he prepares to impose tariffs on all goods imported into America.The US president will confirm the policy at a press conference on Wednesday evening, with the controversial surcharges set to be imposed the following day.Government officials failed to negotiate a special carve-out for the UK in time to avoid the tariffs.It means British-made cars, steel and other products will all instantly become more expensive in the US, dealing a huge blow to the UK economy.The Office for Budget Responsibility last week warned the tariffs will damage economic growth and wipe out the £9.9 billion in spare cash chancellor Rachel Reeves planned to have come 2029.While Canada and the EU have both vowed to retaliate with tariffs of their own on American exports, the UK