In the diplomatic parlour games popular in Brussels, few issues are generating more gossip or being talked about more animatedly than next year's elections to the European Parliament.

They may be 11 months away, but anyone following European affairs closely knows the vote has the potential to shake the ground under the political establishment and bring about a fundamental shift in the balance of power in Europe.

Frustration with how leaders have handled the economic crisis over the past three years, coupled with rising populism, has raised expectations that the anti-European Union vote will surge in the polls.

That would undermine the traditional political blocs, which range across the political spectrum but for the most part are in favour of the EU.

And because they will be the first European elections since the introduction of the Lisbon Treaty in 2009, which gave the parliament additional powers, it means the outcome will directly influence the appointment of the EU's most important jobs.

"Most people I've talked to are predicting that parties on the extreme wings of the politics of Europe, both the far-right and the far-left, will pick up seats in this election," said William Kennard, US ambassador to the EU for the past four years.

"There is a not insignificant prospect that the populists, particularly on the far-right, will have more influence in the parliament than they've had in this particular term, and I think that could affect politics in an interesting way."

If there was any complacency about the potential impact of the vote, which takes place in all 28 EU member states between May 22-25 next year, it was displaced recently by Britain's Nigel Farage, the leader of the right-wing, anti-EU party UKIP.

"There is a gathering electoral storm. It's coming on the left, on the centre and on the right," he warned European Commission President Jose Manuel Barroso, using his most thunderous voice as he addressed the full European Parliament.

"The European elections next year present the opportunity to show you, Mr Barroso, that the European project is reversible and it needs to be reversed for the betterment of the peoples of Europe."

A year is an extremely long time in politics and there is every likelihood that electoral predictions made now will prove dramatically different come April or May next year.

But polling conducted by Gallup and research by Debating Europe, a youth politics group, points to two trends that could prove important: turnout may be substantially higher next year than in the past, and the youth vote may be much stronger.

At every poll since the first direct elections to the European Parliament were held in 1979, turnout has fallen, dropping to just 43 percent at the last vote in 2009.

But in a survey carried out in May, Gallup found 68 percent of Britons would vote if the elections were held next week, double the British turnout at the 2009 ballot. The figures were similar for France, with the survey finding 73 percent of French were ready to vote this time, versus 40 percent in 2009.

Gallup also found increasing disapproval in most large EU countries over the direction in which Europe is moving, suggesting many of those who do turn up to vote could cast anti-EU ballots or go against how they have voted in the past.

Add to that the prospect of hundreds of thousands of young people who have never voted before turning up at the polls, especially those who are unemployed and frustrated, and the election could turn out to be far from predictable.

"Young people are angry and they want to have a voice," Adam Nyman, the director of Debating Europe told Reuters earlier this year. "I don't think they will shy away from the next election."

No one knows how large the anti-EU vote will be, but speculating about it has become a favourite Brussels pastime.

One EU ambassador said recently he had heard talk of up to half the 751 seats in the next parliament being backed by anti-EU or protest votes, then added he thought the figure was excessive and it was more likely to be around 30 percent.

Others see a 25-30 percent "protest vote" as possible, a figure that alarms sitting members of the parliament, who tend to break the issue down into individual member states, where anti-EU or protest parties have their national quirks.

"We could see a rise in nationalistic parties in some countries, such as Britain and France,» said Andrew Duff, a senior member from the Liberal ALDE group who has been in parliament since 1999.

But Duff points out that while there are large and growing protest parties on the left and right in France and Italy, and on the right or left of the spectrum in other, smaller member states, there is not the same clear trend in Germany, the largest and most important member.

Duff still expects the four main political groups - the centre-right European People's Party, the Socialists, the Liberals and the Greens - to come out on top, even if they loose ground from their current standings.

And while there may be a significant protest vote, because it is nationally based and not coordinated as a bloc across Europe, its ability to project influence is limited.

"If we get a protest vote above 25 percent then the organisation of this house is going to be very, very difficult," he said. "It would make life tough for day-to-day business and right away for the nomination of a new Commission president."

The nomination of the next Commission president - one of the two most powerful jobs in the EU - is perhaps the most intriguing aspect of the Brussels parlour game.

Under the Lisbon Treaty, EU member states have to "take into account" the result of next May's elections before proposing a candidate for Commission president. The candidate then has to be elected by a full majority in the parliament.

Many interpret that as giving the EU's only directly elected body greater influence in who ends up heading the Commission, the EU's executive and the only institution with the right to propose legislation, a power the parliament covets.

In the run up to the elections next year, the major groups in parliament will select their top candidate, or perhaps candidates, for the EU's most senior jobs.

There are then plans for televised debates among the candidates to generate buzz ahead of the polls and connect the electorate more directly with Brussels.

In that way, the whole process of electing the parliament, appointing the Commission president and approving his or her commissioners becomes that much more politicised, with parliament front and centre of the process.

It is not for nothing therefore that the current president of the parliament, German Socialist Martin Schulz, is seen as a leading candidate to become the next Commission president.

That's a major shift from the past and has added extra spice to elections that have largely been regarded as a sideshow for most of the last 35 years.

[Reuters]