The Brexit campaign has been told to "get a grip" after going into meltdown over Barack Obama's pro-EU intervention.
The president's warning that leaving the EU would leave Britain at "the back of the queue" for American trade deals has been hailed as a decisive boost for David Cameron's campaign for Britain to stay in the EU.
It triggered a meltdown among senior figures on the Leave campaign, which branded the outgoing president irrelevant and a "lame duck".
Nigel Farage claimed the fact the president used the word "queue" rather than the more common American equivalent "line" showed the remark was written for him by Downing Street.
"He said Britain would be at the back of the queue, no American would ever say 'back of the queue', Americans don't use the word 'queue', Americans use the word 'line'," the Ukip leader told BBC Radio Four's Any Questions.
"Therefore, what Obama said when he said we would be at the back of the queue, he was doing the bidding of Cameron, and Number 10, and doing his best to talk down Britain, and I think that's shameful."
Times journalist David Aaronovitch called this claim "bloody silly".
Ukip MEP Patrick O'Flynn, who jokingly asked if German Chancellor would follow up by threatening to "invade" Britain if it left the EU, argued with Guardian journalist Rafael Behr.
He said: "I think Dave's procuring of thing threat fails a basic patriotism test and we must call him on on that."
Boris Johnson, the Brexit campaign's most colourful backer, has not responded to Obama's gentle castigation of him on Friday evening.
Johnson wrote a column saying the "part Kenyan" president had an "ancestral dislike" of Britain. He claimed Obama had removed a bust of Churchill from the White House.
Obama said he had merely moved the bust to another part of the White House, saying he "loved" the wartime prime minister.
Justice Minister Dominic Raab joined the angry backlash against Obama, saying: "This is really about a lame duck US president about to move off the stage doing an old British friend a favour.
"I have got no doubt that future US trade negotiators are going to look to other opportunities - I think the British will be first in the queue, not at the back of the queue."
Obama also said Britain could not secure a trade deal US "any time soon" if it leaves the EU because Washington's focus would be on reaching agreement with Brussels.
Former Tory leader and ex-work and pensions secretary Iain Duncan Smith moved to switch attention to immigration as he insisted the living wage would provoke a "stampede" to Britain from poorer EU nations.
He wrote in the Daily Mail: "I cheered the introduction of the national living wage, but when take-home pay in Britain is already more than five times higher than in the poorest EU countries, such a jump in wages will surely lead to another stampede to our borders.
"To make the living wage work for British people, we need to be able to control the number of people coming in."
Tory former defence secretary Liam Fox said Obama's views would be irrelevant after the looming US presidential election.
"We have a referendum at the end of June, presidential elections are in November, so whoever it is that will be at the helm of the United States won't be Barack Obama. So, to an extent, whatever he says today is largely irrelevant," he told BBC2's Newsnight.
"It will be the next president, and the next congress, who will be in charge of any trade arrangements."
Leave backer and former foreign secretary Lord Owen told BBC Radio Four's Today programme Obama's trade embarks had been "crafted" in Downing Street.
At a joint press conference with Cameron, the president stressed the referendum was a "decision for the people of the United Kingdom" and he was "not coming here to fix any votes".
He added: "I think it's fair to say that maybe some point down the line there might be a UK-US trade agreement, but it's not going to happen any time soon because our focus is in negotiating with a big bloc, the European Union, to get a trade agreement done.
"The UK is going to be in the back of the queue."
Cameron said the referendum was the "sovereign choice of the British people" but added: "As we make that choice, it surely makes sense to listen to what our friends think, to listen to their opinion, to listen to their views, and that's what Barack has been talking about."
On Saturday, Obama attended a town hall-style meeting in London, where he urged young people to ignore cynics telling them they cannot change the world.
He told them to"reject pessimism and cynicism" and "know that progress is possible and problems can be solved".
He added: "Take a longer, more optimistic view of history."
He received a standing ovation and called Prince George, whom he met on Friday, "adorable."