Former London mayor Boris Johnson, one of the strong voices in favor of the British exit from the European Union invoked the name of Adolf Hitler in his attempt to explain the importance of voting in favor of Brexit.
According to the former mayor, the ambitions of the European Union to create a superstate by unifying the entire continent under one government body is comparable to Hitler's attempt to conquer Europe.
"Napoleon, Hitler, various people tried this out, and it ends tragically," said Johnson in an interview with the Telegraph. "The EU is an attempt to do this by different methods," he added.
Johnson faced immediate backlash for his statements from Labor Party MP Yvette Cooper who accused him of playing a nasty game.
"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," she said in an interview with Sky News.
"The more he flails around with this kind of hysterical claim, the more he exposes his shameful lack of judgement, his willingness to play the most divisive cynical politics, and the emptiness of his arguments," said Cooper.
Johnson, who is a front-runner to succeed Prime Minister David Cameron, has emerged as the most important voice in the "Out" camp.
Cameron, who is leading the "In" campaign, has argued that Britain's membership in the EU makes the country more secure, more influential and more prosperous. He also says Britain, which is not part of the single-currency euro zone, will not be dragged into ever closer union among the EU's member states.
But an opinion poll published earlier on Saturday suggested that twice the number of voters believed Johnson was more likely to tell the truth about the EU than Cameron.
With less than six weeks to go until the referendum, voters are evenly split between wanting to remain in the EU and preferring to leave, other opinion polls have shown.
In his interview with The Sunday Telegraph, Johnson said he wanted the British people to be "the heroes of Europe" again, creating echoes of the language used by war-time prime minister Winston Churchill, the newspaper said.
It also quoted him as saying tensions between EU member states had allowed Germany to grow in power within the bloc, "take over" the Italian economy and "destroy" Greece
Britain votes in a referendum on whether to remain a member of the EU on June 23.