(Reuters) -Around 373 million citizens across the 27 member states of the European Union are eligible to vote on June 6-9 in elections to the European Parliament.

Here is all you need to know about the vote:

WHAT IS THE EUROPEAN PARLIAMENT?    

The European Parliament (EP) is the only directly elected body of the EU, representing the citizens of its member states. Its primary functions include negotiating EU laws with the member state governments, which are represented by the European Council. The EP also approves the EU budget and votes on international agreements and enlargements of the bloc. 

The EP holds significant oversight responsibilities, including the power to approve or reject the appointment of the European Commission president - a post currently held by Germany's Ursula von der Leyen - and the commissioners.

Unlike national parliaments, the EP does not have the right to propose laws but can only negotiate those proposed by the executive European Commission.

The EP comprises 720 members (MEPs) elected every five years. The MEPs then elect their president for a term of two and a half years. The outgoing president is Italy's Roberta Metsola.

WHO CAN VOTE?

In 21 member states, people aged 18 and above can vote. In Belgium, Germany, Austria and Malta, the minimum voting age is 16. In Greece people who turn 17 during the election year can vote, and in Hungary married individuals can vote regardless of age.

EU citizens can vote in their country of origin or from abroad. Voting from abroad is permitted in all member states except Czechia, Ireland, Malta and Slovakia. In Bulgaria and Italy that right applies only to those living within the EU. 

Citizens living in another EU country can choose to vote for candidates either from their country of origin or from their country of residence. 

The voter has to choose which country's MEPs he or she will vote for, but it is not legal to vote in both countries at the same time.

HOW TO VOTE?

In some member states, voters can only choose closed lists that do not allow change of order for preferred candidates, while in others they can select individual candidates in a preferential system.

Depending on national laws, some electors abroad can vote at their national embassies, via mail or electronically.

WHO CAN RUN AS A CANDIDATE? 

Voters may choose from individual candidates or political parties' delegates, depending on the country. Once elected, politicians from each nation will flow into the European groups that form the Parliament, based on political orientations. 

Some member states, including Germany, only allow candidacy in European elections for nominees of political parties or political associations. 

Elected individuals cannot hold functions in national governments or other political bodies such as the EU Commission, the Court of Justice or the Court of Auditors, among others. All candidates must be EU citizens.

2024 ELECTION PREDICTIONS

Six in 10 EU citizens have expressed their interest in voting in these elections, a survey by the bloc's statistics agency Eurostat showed in April.

A projection by poll aggregator Europe Elects forecast at the end of May that out of the 720 seats available in the EP, the Group of the centre-right European People's Party (EPP) would win 180, the centre-left Progressive Alliance of Socialists And Democrats (S&D) 138, and the liberal, centrist Renew Europe (RE) 86.

The European Conservatives and Reformists (ECR) would have 75 seats and Identity and Democracy (ID) would be down to 68 from 84 in April, after expelling Germany's far-right Alternative for Deutschland (AfD). Other smaller parties would win the remaining 173 seats, the data from Europe Elects showed.

2019 ELECTION RESULTS

The previous elections marked a pivotal shift in politics as traditional centre-right and centre-left blocs lost ground to smaller parties.

The EPP and centre-left Progressive Alliance of Socialists and Democrats (S&D) saw their combined number of seats drop by 76, losing their long-standing majority. 

This necessitated broader coalition-building, boosting centrist and pro-EU groups such as Renew Europe and Greens/EFA.

Voting turnout hit a 20-year high at 50.66%, an 8% increase from 2014, indicating heightened public interest in issues such as climate change, migration and economic inequality.      

(Reporting by Alberto Chiumento, Luca Fratangelo, Marta Maciag, Anna Maria Nowak, Alessandro Parodi, Mateusz Rabiega; editing by Gareth Jones)