Theresa May has revealed that Donald Trump's private advice to her on how to resolve deadlocked Brexit talks was to sue the European Union.

On The Andrew Marr Show on Sunday morning, the prime minister disclosed what Trump had told her after the US president criticised her approach to the Brexit negotiation in a controversial newspaper interview.

In a joint press conference on Friday, Trump had alluded to his private advice, which he admitted was "brutal" but declined to say what it actually was.