Each country decides on the form its election will take, but must guarantee equality of the sexes and a secret ballot. EU elections are by proportional representation. Voting age is 18, aside from Austria, where it is 16.
Seats are allocated on the basis of population of each Member State. Slightly more than a third of MEPs are women. MEPs are grouped by political affinity, not nationality.
MEPs divide their time between their constituencies, Strasbourg - where 12 plenary sittings a year are held - and Brussels, where they attend additional plenary sittings, as well as committee and political group meetings.
The terms and conditions for Members are laid out in the Statute of 2009.