Boris Johnson is at the centre of a political storm after he compared European Union efforts to build a superstate to Hitler's attempt to dominate the continent.
While the former London mayor acknowledged the EU was using "different methods" to the Nazis, his incendiary comparison to the Third Reich drew a furious response from Remain campaigners.
Johnson - seen as the de facto leader of the Leave campaign - said the past 2,000 years of European history had been dominated by doomed attempts to unify the continent under a single government to recreate the "golden age" of the Romans.
"Napoleon, Hitler, various people tried this out, and it ends tragically. The EU is an attempt to do this by different methods," he said in an interview with The Sunday Telegraph.
"But fundamentally what is lacking is the eternal problem, which is that there is no underlying loyalty to the idea of Europe.
"There is no single authority that anybody respects or understands. That is causing this massive democratic void."
His comments were immediately condemned by the Britain Stronger In Europe campaign, with Labour former cabinet minister Yvette Cooper accusing him of playing a "nasty, nasty game".
"The more he flails around with this kind of hysterical claim, the more he exposes his shameful lack of judgment, his willingness to play the most divisive cynical politics, and the emptiness of his arguments," she said.
"One week it is dog whistle attacks on President Obama. Now he is trying to liken the institution that has kept peace on our continent for decades with Hitler, who pursued the genocide of millions of innocent people.
"All because he is desperately seeking headlines for a desperate campaign. He should not try to play political games with the darkest and most sinister chapter of Europe's history.
"The EU has played a critical role keeping peace in Europe ever since."
Meanwhile, people on the internet are debating over what Johnson's comments mean and some of them are not on board...
When you compare the EU to Hitler then you've clearly run out of ideas and are desperate.
-- Harry Neary (@Grumpyrocker) May 15, 2016
-- Dean (@DeanMThomson) May 15, 2016
EU to Hitler ...poor old baffled Johnson....when you're not the sharpest knife in the draw always play Hitler as your trump card
-- Ethan Wood (@ethan_wood__) May 15, 2016
-- geoff archer (@geoffarcher5) May 15, 2016
-- Stu Hardy (@H4rdMan) May 15, 2016
Boris compares EU to Hitler. Because we often think of easier travel, easier trade and enhanced human rights when people say 'Hitler' :/
-- Cllr Cody McCormick (@councillorcody) May 15, 2016
While there are others who believe Johnson's remarks may have been misconstrued...
"Eu to Hitler" fair comment when read in context and not reacting to the headline.People do love a bit of faux rage and overeaction
-- Martin Harrington (@Strawbs86) May 15, 2016
EU to Nazi not what Boris was going on about, but when you ignore the wishes of the majority they will turn to the extreme right for answers
-- English Cad (@englishcad) May 15, 2016