An overview of European elections and how voting differs across countries

Each country in the European Union has its own rules for voting in the May 23-26 elections to the bloc's parliament. Here is an overview.

Who votes when?

Twenty-one of the EU's 28 members goes to the polls on May 26, a Sunday, including France, Germany and Poland.

Britain and The Netherlands vote on Thursday, May 23; Ireland on the 24th; Latvia, Malta and Slovakia on the 25th.

In the Czech Republic, voters have two days to get to polling stations, the 24th and 25th.

Three methods, 28 variations

The allocation of seats to the European Parliament is based on proportional representation.

However, within the member states, there are three different procedures for electing Euro-MPs.

- The preferential vote system is used in 19 countries, including Italy, Poland, The Netherlands and the Scandinavian nations.

Here the voter can, depending on the country, change the order of the names on a party list to boost their preferred candidate; remove candidates from a list; or even pick and mix candidates from various lists.

- The closed ballot allows voting only for a single party list in which the candidates and the order in which they are ranked are fixed.
The lists are defined by parties with preferred candidates at the top. This method means voters cannot select individuals.

It is used in seven countries including Germany, France, Spain and Britain outside of its Northern Ireland constituency.

- In the single transferrable vote -- used in Malta, Ireland and Northern Ireland -- voters do not work off party lists but choose only individuals, ranking candidates by order of preference.

Compulsory voting

Voting is compulsory in five member states: Belgium, Bulgaria, Cyprus, Greece and Luxembourg.

Belgium and Luxembourg can even issue fines in case of a no-vote.

Regional constituencies

Most EU member nations vote for parliament as single entities but five map out regional constituencies.

Belgium has three constituencies, defined along language lines. The others are all geographical: 13 in Poland, 12 in Britain, five in Italy and three in Ireland.

Post, proxy and internet

Sixteen countries allow voting by post, in most cases for the benefit of citizens living abroad.
They include Britain, Germany, Spain and the Nordic nations.

Six countries allow proxy voting in which a person can ask someone else to vote on their behalf. In Belgium, Britain, France and The Netherlands, this option is available to everyone. In Poland and Sweden, it is reserved for voters who are unable to go to a voting station, including because of age or disability.

Voting online is allowed only in tech-savvy Estonia.

Representation of women

Eleven countries impose gender quotas on candidate lists.

In Belgium, France, Italy and Luxembourg the lists must feature the same number of men and women. In Croatia, Spain and Slovenia at least 40 percent must be of one sex, dropping to 35 percent in Poland and 33 percent in Greece and Portugal.

In Romania, at least one woman, or one man, must be included on each list.

Some countries have measures in place to ensure gender quotas are met but sanctions are not always enough to make parties oblige.

While non-conforming lists are nullified in Greece, in countries such as France and Luxembourg the only risk is fine.

Minimum age

In all but three countries, the voting age is 18. In Greece, it is 17, and Austria and Malta allow voting at 16.

For candidates, in 15 countries the minimum age is 18. It rises to 21 in 10 others, including Poland and the Czech Republic.

In Romania, a candidate must be at least 23 years old and in Italy and Greece the minimum age is 25.