Donald Trump has permitted his former campaign coordinator, Chris LaCivita, to publicly insult Keir Starmer’s choice for the UK’s new ambassador to the US. This revelation comes with a warning that Sir Keir has turned the special relationship toxic as sources suggest the prime minister had ignored demands by the Trump transition team that Peter Mandelson not be appointed. The anger is such that one source said Mr Trump may use his veto to block the choice, though this is seen as unlikely.

The Trump team’s rage at the decision to appoint Lord Mandelson, nicknamed the Prince of Darkness, as the ambassador in Washington has been revealed. Following the announcement, Trump’s campaign coordinator, Chris LaCivita, posted on X late on Friday that Lord Mandelson is a “moron.” He wrote: “This UK government is special. Replace a professional universally respected ambassador with an absolute moron – he should stay home! SAD!”

Mandelson described Trump as a danger to the world and ‘little short of a white nationalist’. Now it has emerged that he was given permission to insult Lord Mandelson by the president-elect himself, according to insiders. The Labour government had approached the Trump transition team about the intention to appoint Lord Mandelson, a former spin doctor, cabinet minister, and EU commissioner.

There have been questions over whether Sir Keir will have an invite to the inauguration next month, while Reform UK leader Nigel Farage will be hosting one of the main parties ahead of the event in Washington. Italian Prime Minister Giorgia Meloni and Hungarian PM Viktor Orban are already guests of honour at the inauguration itself.