British Prime Minister Gordon Brown fired the starting gun Tuesday on a month-long election race, setting May 6 as the date for voting in what could be the closest-run poll for a generation. A stern-faced Brown made the announcement in Downing Street flanked by his entire Cabinet after visiting Buckingham Palace to ask Queen Elizabeth II to dissolve parliament. "It's probably the least well kept secret of recent years, but the queen has kindly agreed to the dissolution of parliament and a general election will take place on May 6," he said. Brown's confirmation of a date widely reported for weeks triggers a month of campaigning in which his centre-left Labour will battle David Cameron's centre-right Conservatives, who are ahead in opinion polls. If Labour wins, it will be the party's fourth consecutive term in office and its first under Brown, who took over as leader from Tony Blair in 2007. The Tories are vying for their first victory since a surprise win in 1992.