London - Britain went to the polls yesterday in elections that David Cameron's opposition Conservatives hope to win for the first time since 1992. Here is a summary of how the British electoral system works. - Britain's prime minister can announce a general election at any time during their term of office, after first asking the monarch to dissolve parliament. - The country does not have fixed-term parliaments but elections must be held at least every five years. - Britain operates a first-past-the-post voting system for general elections in which England, Wales, Scotland and Northern Ireland are divided up into 650 constituencies. - Parliamentary constituencies historically each comprise roughly 70 000 voters but the boundaries are only redrawn every decade or so, and currently vary in size from 22 000-110 000 voters. Each elects one MP (member of parliament) who sits in the House of Commons. - Every person in that constituency can cast one vote for who they want to be their MP. Voters do not directly elect the prime minister. - Assuming a party secures an overall majority - at least 326 members - in the House of Commons, its leader is asked by Queen Elizabeth II to form a government and also becomes prime minister. - If no party has an overall majority in the House of Commons, there will be a hung parliament - an extremely rare event in Britain that has not happened since 1974. But polls suggest this could be happen in the 2010 vote. - This could lead to a minority or coalition government. - However, the precedents for this lasting long-term are not promising - in 1974, two elections were held within nine months to resolve the situation. - As well as being leaders of their parties, Labour Prime Minister Gordon Brown and Conservative leader David Cameron are also constituency MPs.
