Factbox: A United Kingdom divided over Brexit - Results of EU election

LONDON (Reuters) - Nigel Farage's Brexit Party romped to victory in the European Parliament election, with both Prime Minister Theresa May's Conservatives and the opposition Labour Party losing support across the country. WHAT DO THE PRELIMINARY RESULTS SHOW? The Brexit Party came out on top and smaller pro-European Union parties also gained ground, while the Conservatives and Labour hemorrhaged votes to parties that took unequivocal positions for or against Brexit. WHO GETS ELECTED? The United Kingdom is divided into 12 electoral regions - nine in England, and one each for Scotland, Wales and Northern Ireland. In total it will elect 73 MEPs (Members of the European Parliament). WHAT SYSTEM IS USED? In Britain, parties submit a list of candidates for each region and voters select a party rather than an individual candidate, unless they are backing an independent. As the seats are allocated to a party, they in turn allocate them to candidates starting from the top of their list. In Northern Ireland, as votes are counted the candidate with the least votes in eliminated and their votes redistributed. This is repeated until there are only the required number of candidates left for the number of seats available. ISN'T THE UK LEAVING THE EU? Britain is taking part in the elections because it delayed the date of its exit from the EU, but its MEPs will leave the parliament when Brexit happens. Sources: UK Electoral Commission, European Parliament, regional election officials (Writing by Guy Faulconbridge and Kate Holton; Editing by Catherine Evans)