LONDON (Reuters) - When Nigel Farage rolls into town in a purple double-decker bus to campaign for Britain to leave the EU, the music blaring from the loudspeakers is from the classic World War Two movie "The Great Escape".
"That's what we need, isn't it? A great escape from this European Union!" Farage told cheering supporters as his bus arrived at a recent campaign stop, a typical scene as he tours Britain ahead of its June 23 referendum on EU membership.
Critics say it is outrageous to suggest a parallel between a tale of British and allied prisoners of war escaping from a Nazi camp and the prospect of the United Kingdom leaving the EU, but supporters of Farage's UK Independence Party love it.
"This has to be the best campaign tour! The 'Great escape' theme :) what a brilliant choice. Makes you proud to be British!" wrote user @Mat_Griffin on Twitter.
Memories of World War Two are central to many Britons' self-image as an indomitable island people. Historians say the contrast with fellow EU member nations which experienced fascist rule and foreign occupation is a main reason why Britain has struggled to find its place in the bloc.
Talking about the war is a reliable way to tug at patriotic heartstrings, and both sides in the EU debate have been doing it.
Prime Minister David Cameron, campaigning to keep Britain in the bloc, recounted in a speech last month that when he departs for EU summits from a Royal Air Force base, he passes a Spitfire, the fighter plane that helped to repel Adolf Hitler's Luftwaffe.
"Like any Brit, my heart swells with pride at the sight of that aircraft," he said.
Cameron went on to argue that it was not by choice that Britain stood alone against the Nazis in 1940, after the fall of France and before the United States entered the war, and that wartime leader Winston Churchill had never wanted isolation.
"In the post-war period he argued passionately for Western Europe to come together ... so that our continent would never again see such bloodshed," Cameron said.
Churchill's grandson Nicholas Soames, a member of parliament, has said Churchill would have voted "Remain".
But the "Leave" camp argues that he did not want his country to be fully involved in European integration and would therefore have backed a British exit.
"All of the evidence about Churchill's view on the matter says he wanted Britain to be a separate sponsor and friend to the developing union in Europe," said Julian Thompson, a retired major general who chairs pro-Brexit group Veterans for Britain.
Treading into even trickier territory, "Leave" campaigner and former London mayor Boris Johnson argued that the EU and Hitler were part of the same long history of doomed attempts to dominate Europe.
"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 a newspaper interview.
The comments by Johnson - a senior member of Cameron's Conservative party which is divided on the issue - caused a row that dominated the campaign for days on end.
The shadow of Hitler was also present on the front page of The Sun, Britain's top-selling newspaper, when it mocked a package of reforms obtained by Cameron that he said gave Britain "special status" within the EU.
Referring to "Dad's Army", a hugely popular BBC TV comedy about a group of hapless older men volunteering to defend Britain against Nazi invasion, the Sun asked: "Who do you think you are kidding Mr Cameron?"
This was the first line of the Dad's Army theme tune, except that in the original, the question was addressed to "Mr Hitler".
editing by David Stamp