British Prime Minister Gordon Brown calls a general election for May 6

British Prime Minister Gordon Brown has launched a month-long election campaign likely to be dominated by the economy. The May 6 election is shaping up as the most unpredictable contest since 1992. The opposition Conservatives lead Labour in opinion polls. But the election result is far from certain as public support for both main parties remains volatile. Polls point to a hung parliament in which no party has an overall majority