There's been a deluge of reaction - much outraged, but also supportive - after the US president used his UK visit to attack PM Theresa May's Brexit plans.
There has been a torrent of passionate reaction to President Donald Trump's interview in The Sun in which he lambasted Prime Minister Theresa May over Brexit, saying the UK leader's plan would "probably kill" any trade deal between the United Kingdom and the United States.
Many politicians and others have expressed outrage at the US president's intervention, which was published as he was being hosted by Theresa May at a lavish dinner. However, pro-Brexit supporters who criticise the prime minister's blueprint for keeping the UK too close to EU rules see his comments as backing their demands for a cleaner break from the bloc.
Here is a selection of Friday's comments in a row that has exacerbated the divisions over Brexit, coming at a crucial stage of London's negotiations with Brussels over the UK's departure.
Junior UK minister for science, Sam Gyimah, tweeted: "Where are your manners, Mr President?" Another leading Conservative, the pro-EU Sarah Wollaston, said May would greet her guest politely, before using Trumpian language herself to say "many will be cheering if she tells @realDonaldTrump where he can stick his dog whistle".
The Minister for Digital and the Creative Industries had a succinct reply to Donald Trump's assertion that Boris Johnson would make "a great prime minister". No, tweeted Margot James, the ex-foreign secretary "would make a terrible PM".
Opposition Labour MPs weighed in, too. Former minister Ben Bradshaw called Trump's intervention "humiliating" for the prime minister. Shadow foreign secretary Emily Thornberry said she felt sorry for May: "You don't, when you go to someone's house, insult the host".
However, Trump's comments have been backed by critics of the government's Brexit plan. Arch-Brexiteer and former UKIP leader Nigel Farage — who Trump has suggested should be the UK's ambassador to the US — went on the US president's favourite news channel Fox News to say that he was right.
Jacob Rees-Mogg leads the hardline pro-Brexit European Research Group of Conservative MPs. He has fired off a fresh series of tweets criticising May's Brexit plan, claiming that "President Trump clearly understands the white paper better than some ministers".
Earlier, Rees-Mogg told BBC Radio that Trump's comments were "a perfectly reasonable thing for an American president to say, adding that "if you can't do a trade deal with your closest ally, who can you do a trade deal with?".
Ian Paisely Jr of Northern Ireland's Democratic Unionist Party (DUP), on whose support in Parliament May's government depends, defended Trump's Brexit intervention on Sky News as "a wake-up call for the UK".
But will the US president's "bombshell" have a lasting impact? Law and policy commentator David Allen Green believes not, asserting there is little chance of a US-UK trade deal under Trump, anyway.
Bloomberg reports that developments like this, that appear to make May's position more precarious, may actually encourage the EU to come to her aid — for fear of seeing her downfall herald something far worse.