Can you guess who bought the most cognac? Kim Jong-Il revealed as Hennessy¿s biggest customer spending £700,000 a year on the brandy Kim Jong-Il was reportedly Hennessy's biggest customer Whisky lovers include successful UK leaders Churchill, Thatcher and Blair Research claims those who drink pints never peak in the politics North Korea's late leader Kim Jong-Il was reportedly the biggest client fro cognac brand Hennessy and spent £700,000 on the drink. The fact was dug out in research into leaders' favourite tipple, which has suggested politicians success might have something to do with their preferred drink. Some of the UK's top leaders have all opted for whisky, while across the Atlantic in America, they have a sweeter tooth, preferring a cocktail. Whisky verses pints: Tony Blair was one of a number of successful politicians who prefer to drink whisky, as opposed to John Prescott who opted for a pint The research, carried out by online drinks firm 31DOVER.com, revealed that Churchill, Thatcher, Blair and Cameron have all shown a mutual affection for whisky, with Churchill setting himself up for a day of success by rounding off breakfast with a whiskey soda. He was also partial to the odd drop of Pol Roger, which led to Cuvée Sir Winston Churchill champagne being named after him. Tony Blair was a little more measured in his love of his chosen liqueur as he was 'never sure' if his daily scotch before dinner would be good or bad for him. No such uncertainty for the late Margaret Thatcher, whose fondness for Bell's was legendary. Whisky also worked its magic for the current Prime Minister, though his taste is a little more expensive. Expensive taste: North Korean leader Kim Jong-il (R) was reportedly the biggest single customer of Hennessy cognac. The late leader is pictured in 2000 with then South Korean President Kim Dae-jung David Cameron, who counts Thatcher as one of his greatest inspirations, enjoys Bruichaladdich's organic single malt, priced at £41 a bottle. While whisky has helped politicians prosper, pints have led MPs to their peril, the researcher claim. John Major, David Milliband and John Prescott all have a passion for a pint but have faced troubles in their political career. John Major famously presided over a string of political embarrassments including the 1992 Black Wednesday financial collapse; the older Milliband was defeated by his brother in the Labour party's leadership contest; and Prescott, the former Deputy Prime Minister tried to resurrect his political career but failed after losing out as then Police and Crime commissioner. Similar tastes: British Prime Minister David Cameron, pictured last week in Kabul Afghanistan, likes to drink pricey whisky Bruichaladdich, while Margaret Thatcher loved cheaper Bell's Across the Atlantic, political success is about mixing it up. Former U.S. presidents John F Kennedy and Bill Clinton both enjoyed a feminine cocktail with Kennedy sipping on a Daiquiri and Clinton a La Señorita, containing tequila, pineapple juice, lime juice and Tabasco sauce. Famous teetotalers include former President George W Bush and Adolph Hitler. Presidential candidate Bill Clinton, pictured in 1992, and the late President John F. Kennedy, in 1961, both enjoyed feminine cocktails David Laurie, chief executive of the online drinks firm, said: 'It's interesting that so many famous political figures have had such a strong penchant for a particular tipple. 'Equally notable is that so many of them drink or drank neat spirits which is a trend we're seeing return among men and women today.'