UK 27 September 2012 Cameron fails citizenship test on David Letterman show Prime Minister left red-faced after he fails to give the English for Magna Carta. Sign up for our weekly email * Print HTML While it wasn't the toughest interrogation he'll ever face, David Cameron still endured several awkward moments during his appearance on the David Letterman show last night. Challenged by Letterman to name who composed Rule Britannia as part of a mock British citizenship test, Cameron incorrectly answered "Elgar" (the correct answer, as revealed at the end of the show, was the little-known Thomas Arne). Less forgivable, perhaps, was the Prime Minister's failure to know the English for Magna Carta (Grand Charter), an omission that won't have impressed the Latinophile Boris Johnson. "You have found me out. That is bad, I have ended my career on your show tonight," Cameron joked at one point. He went on to redeem himself, in the eyes of US viewers at least, by successfully explaining the difference between Northern Ireland and the Republic of Ireland and by displaying some awareness of the complex history of Anglo American relations. "We interfered in your politics 200 years ago when we sailed up the river and burnt the White House," Cameron said, in reference to the war of 1812. The full video isn't available yet, but you can watch a short clip of the interview above. › Last Chance for Arab Cinema David Cameron joked "I have ended my career" after stumbling over a series of questions on British history. George Eaton is political editor of the New Statesman. Subscribe from just £1 per issue More Related articles Will Storm Doris affect turnout in the Stoke-on-Trent and Copeland by-elections? What does it mean for Ukip if it loses in Stoke-on-Trent Central? What does François Bayrou's endorsement of Emmanuel Macron mean for the French presidential race?