The European Parliament (EP) completed its seventh term on Thursday, bringing to an end perhaps the most eventful sitting since the institution was established.

Over the past five years, the EP adopted 970 legislative acts most of them against the backdrop of the eurozone crisis, a deep economic recession in many member states, and growing disenchantment among voters at the entire European project.

The new, eighth, Parliament will be constituted on July 1, after elections held from May 22 to 25. The vote will be the biggest yet; the 751 MEPs elected will represent more than 500 million citizens in 28 member states.

A major new development this time is that when member states nominate the next president of the European Commission to succeed Jose Manuel Barroso in autumn 2014, they will, for the first time, have to take account of the European election results. Effectively, the chosen candidate of the largest political grouping following the polls will be selected as the next Commission president.

Of the 13 parliamentary groupings, five have nominated a candidate to succeed the current president. Of the leading contenders, the centre-right EPP group has chosen Jean-Claude Juncker, former prime minister of Luxembourg and former Eurogroup president. The centre-left's PES candidate is Martin Schulz, current president of the European Parliament, while the Liberals and Democrats have opted for Guy Verhofstadt, former Belgian prime minister and current Liberal group leader in the EP.

But opinion polls suggest the elections will also see big gains for populist parties whose views on deeper European integration range from deeply sceptical to outwardly hostile.

The stakes are particularly high this year because the economic crisis has sharpened the debate about the EU's future. If enough voters express their mistrust of the EU's institutions by voting for parties largely hostile to the union, a big anti-EU bloc could significantly disrupt the workings of the next parliament.

Opinion polls suggest that Marine Le Pen's Front National (FN) in France, Geert Wilders's Party for Freedom (PVV) in the Netherlands, and Nigel Farage's UK Independence Party (UKIP) will make big strides in this year's elections. However, it is by no means certain that all these groups will find common purpose in forming a specific bloc.

Most FN and PVV MEPs are currently in a non-aligned group, as are some UKIP MEPs, but interestingly not Farage and some of his other supporters, who have put their weight behind the Europe of Freedom and Democracy Group. Italy's Lega Nord is also a leading force in this group.

In fact, the potential for disagreement among the populist groups remains real, meaning they could spend too much time squabbling among themselves to form a solid power base. To form a parliamentary group, which would receive official funding, they would need at least 25 MEPs from seven different countries.

On the other hand, countries like Spain and Portugal, which have suffered far more during the economic crisis, show little sign of falling for populist rhetoric. There, mainstream centre-left and centre-right groups are still expected to hold on to the dominant positions in the next EP.

There is, of course, still much work for the next parliament to do. This week, the EP passed new legislation going some way towards creating a banking union seen as necessary to minimize the impact of future financial crises. But this project is far from complete and it is by no means clear that national governments, even in countries within the eurozone, are really prepared to swallow further integration.

But perhaps the greatest challenge of all is public indifference. Each European election has seen a decline in turnout, from 63 percent for the first one in 1979 to a mere 43 percent in 2009. This tends to favour the more extreme parties, but is also a symptom of a widespread belief that the entire European project is beyond the control of Europe's citizens.