The South East has ten seats and the South West has 6 seats.
The first elections to the European Parliament were held in 1979. Since 1999 the UK has used a closed list system of proportional representation to elect its MEPs.
In European elections in the UK electors vote for parties rather than individual candidates. Each party then lists its candidates in the order they want them elected.
If a UK MEP dies or retires there is no by-election - the next candidate on the party list is invited to take their place for the rest of the parliament.
The method of calculating the distribution of seats after the votes are counted is named after a nineteenth century Belgian Mathematician, Victor D’Hondt.
In the last European elections in 2009 turnout varied between 95.6% in Luxembourg and 19.6% in Slovakia - UK turnout was 34.7% which is just below the average of 43%. I
Every party standing in a region has to pay a deposit of £5,000 which is refunded as long as they get at least 2.5% of the vote locally.
British citizens living in other EU countries are eligible to vote there and likewise EU nationals living in the UK can vote in the election in our region.
EU citizens are eligible to stand in these elections in any of the 27 EU nations, unless local laws ban them from standing in national elections - which means that Hungarian police officers, Spanish TV directors and Austrian bank directors are banned from standing.
You cannot be a member of the European Parliament and be a member of a national parliament which meant Green MEP Caroline Lucas had to stand down after she became the MP for Brighton Pavilion in the 2010 General Election.
The European Parliament has 754 MEPs - Germany has the largest group with 99 MEPs followed by France with 74, and the UK and Italy with 73. Ireland has 12 MEPs and the smallest groups are Cyprus, Estonia, Luxembourg and Malta with six each.
The European Parliament employs 700 full-time translators and 430 staff interpreters to deal with the 23 official languages in the parliament - this accounts for a third of the parliament’s 1.7 billion Euro annual expenditure.
There are almost 200 different political parties represented in the European Parliament - 12 of them from the UK.
Voters must register by May 6 in order to be able to vote on May 22 and the deadline for applying for a postal vote is 5pm on May 7.
Parties will be listed alphabetically on the ballot paper (with the list of candidates under the party name), followed by an alphabetical list of any individual candidates. Electors vote by placing one cross next to the party or individual they wish to vote for.