To coincide, BBC News Online is giving you the chance to put your questions on how the election will affect you to our expert team of correspondents in Brussels.

Here BBC correspondents Stephen Sackur and Oana Lungescu answers some of your questions:

Question:I am a UK citizen who believes in the principle of a federal Europe - which party should I vote for? Nick Fraser

Stephen Sackur: I wouldn't presume to tell you who to vote for, but it's worth pointing out than none of the main British political parties advocate a federal 'United States of Europe'.

The EU as currently constituted is a voluntary union of nation states which have 'pooled' their sovereignty in certain key areas - the single market, agriculture etc - to provide for more efficient cooperation.

As the current debate over the EU constitutional treaty shows, British political parties have divergent views about the precise balance between the rights and functions of the nation states and the common EU institutions.

Even within the major parties there are differences between those politicians who would describe themselves as 'EU enthusiasts' and others who are avowedly sceptical.

All I can suggest is you read the party manifestos carefully and see whose content and tone most closely matches your own obvious enthusiasm for more European integration.

Question:What does the European Parliament add to European democracy when Member States all have elected national parliaments and governments? Ally, Dublin

Oana Lungescu: The European Parliament is the only directly elected EU body, unlike the other two main institutions - the Council, which is made up of representatives of EU governments and the European Commission, whose members are also appointed by the governments.

In fact, it's the only directly elected trans-national body in the world. It's also the only institution that scrutinises EU legislation line by line as it's proposed, rather than after it's adopted - so from that point of view its role is crucial for democracy.

Until 1979, its members were selected among the national parliamentarians of the member countries, but with time, the increased volume of work made it impossible for them to exercise their mandate both at home and in Strasbourg.

The draft European Constitution proposes a "yellow card" principle, which means that when one third of national parliaments challenge an initiative from the European Commission, it has to be reconsidered.

The Parliament can and does reject proposals from the European Commission and often strikes a hard bargain with the Council of Ministers over proposed legislation.

Last April, for instance, it asked the European Court of Justice to rule if an EU/US agreement to disclose air passenger data provides enough protection for EU citizens.

Question:Is there an entity within the commission which is in charge of promoting the implementation of a common language for the EU? Maxime Yartifpov, Paris, France

Oana Lungescu: No there isn't. So don't expect esperanto to become the official language of the EU any time soon!

It's true that the French fear English becoming the dominant language in the EU, as more people speak English than French in the new member states from central and eastern Europe.

That's why they're spending one million euros to send European Commissioners and other EU officials on French language courses.

At their regular meetings, ministers from the 25 member states often use one of the two working languages - French and English - to speed things up.

They may even switch from one to the other in mid-sentence. But they can't all be expected to be multilingual, so they have the right to speak in their own language.

This is particularly useful in highly technical or politically sensitive discussions.

All 83,000 pages of EU rules and regulations are also supposed to be available in all the 20 official languages, although there have been serious delays in translating them, especially in the new member states.

In fact, enlargement has raised concerns that the EU is becoming a Brussels Tower of Babel.

But that may be inevitable since one of the guiding principles of the EU (now enshrined in the Charter of Fundamental Rights) is respect for linguistic and cultural diversity.

Question:As a long-term foreign resident living in France. I am obliged to vote for a French candidiate. However, apparently neither I, nor any other non-French person can stand for the EU parliament, if not living and voting in our country of origin. (Only French Nationals can be elected in Regional elections and then into EU Parliament). Doesn't this make a mockery of a "united" Europe if Nationality comes first? Shaun Smyth, Divonne, France

Oana Lungescu: Any EU citizen can stand for the European Parliament in any member state, though in reality, few take the opportunity to do so.

In France, President Chirac ran into some opposition from his UMP party after he allegedly imposed the Finnish racing driver Ari Vatanen as number two on the European election list in Toulouse.

He's the only foreigner running for the UMP. But The Greens are fielding two foreign candidates in France - one Polish, one German. One of the Green leaders, Daniel Cohn-Bendit, who is currently a French MEP, will be running in his native Germany this time round.