Foreign Secretary Yvette Cooper has reminded her US counterpart Marco Rubio of his obligations under international law, she told MPs, following US military action in Venezuela.
US President Donald Trump's launched an operation resulting in the capture of President Nicolás Maduro this weekend, leading to accusations the US had flouted international law.
Cooper's statement to the House of Commons went further than Prime Minister Sir Keir Starmer, who has so far avoided condemning Trump's decision and focused instead on the brutality of Maduro's dictatorship.
In a stormy debate, Conservative leader Kemi Badenoch said she was disappointed not to hear from the prime minister on the issue.
The government has been facing growing calls to speak out against Trump's action, with Emily Thornberry, the Labour chair of the Commons Foreign Affairs committee, saying the UK should "be clearer that this has been a breach of international law".
