'Union Jack' flag of the United Kingdom (L) and flag of European Union are pictured on May 29, 2015, in front of the Chancellery in Berlin, Germany, prior to a meeting of German Chancellor and British Prime Minister. British Prime Minister Cameron is on a two-day tour of European capitals in a bid to secure EU reforms as his government published a law paving the way for a vote on whether Britain should leave.  AFP PHOTO / ODD ANDERSEN        (Photo credit should read ODD ANDERSEN/AFP/Getty Images)