Voters gathered historic referendum, in which they discussed the membership of the United Kingdom in the European Union, taking into account public opinion. A record number of people - nearly 46.5 million - registered to take part in the vote, which is usually once in a generation. Registered voters include the Britons of England, Wales, Scotland, Northern Ireland and Gibraltar - a British territory off the southern coast of Spain. The question that they pondered for several months: will the United Kingdom member of the European Union or leave it? British citizens over the age of 18 living in the UK, there is expected to cast its verdict in the ballot box. British citizens living abroad already cast their votes by mail. Polling stations across the UK opened at 7 a.m. local time (2 a.m. Eastern time) and will end at 10 p.m. (5 p.m. Eastern time). Final, single result is expected to be announced on Friday morning. The UK is a member of the European Union since 1973. After the results are known they will be announced by regions, not by constituency. 12 regions including Scotland, Northern Ireland, Wales, London and the eight English regions.