King Charles III arrives in Washington today with Britain hoping the royal touch can help ease increasingly strained relations with the US.

UK Prime Minister Keir Starmer has infuriated US President Donald Trump by refusing to take part in the Iran war; in theory the state visit is unrelated, but Downing Street hopes it might lower the temperature.

Trump likes Charles and royal pomp, but there are potential flashpoints, not least the administration’s recent comments about UK sovereignty over the Falkland Islands. Starmer — who is facing relentless domestic criticism over a flailing economy and his appointment of the disgraced Peter Mandelson as ambassador to Washington, while grappling with a surging far-right opposition — will be praying for a smooth visit.