Mr. Buruma, Bill Clinton said in his 1992 presidential campaign: "It's the economy, stupid"! And this may as well be "the trouble with Europe"!

More than half a century ago, it was the disastrous aftermath of World War II which underlay the imperative to forge stronger ties among nations in Europe to guard against any such devastation recurring. French statesmen Jean Monnet and Robert Schuman were the architects of the principle that the best way to bring nations closer together was by developing economic ties.

Today it's the economy again, that might spoil this spirit. In times of economic downturn, citizens in each country believe they should look out for themselves. As nationalism is on the rise, so are resentments towards the EU policies, especially in economic issues. A tug of war between nationalism and European federalism is unfolding ahead of the election.

Pundits predict that "the big winners in the European Parliament election later this month will be right-wing populist parties that share a common loathing of the European Union". True, yet although they share the same anathema, they don't always have the same agenda and they try to outdo each other.

Recently an open warfare has broken out between two of Europe's leading Eurosceptics. Marine Le Pen, leader of France's National Front (FN), has accused Nigel Farage, head of the UK Independence Party (UKIP) of labelling her party "racist". Farage had rejected ties with the FN for its "anti-Semitism and general prejudice".

Le Pen belittled the UKIP, saying its members were "a bunch of drunks and racists", a phrase used by David Cameron and insisted Farage were no better. She blamed it on an old rivalry "between France and England", as both couldn't agree on who should be the top dog after the election. Indeed recent polls have showed that Eurosceptic groups are posing a threat to established parties. UKIP and FN are said to come top in their own countries. Likewise Italy's Five Star Movement and other far-right fringe parties elsewhere.

But the Le Pen-Farage row also highlights the difficulties that Eurosceptics may have in forming a cohesive bloc in the European Parliament. UKIP has rejected ties with parties with far-right reputations, like the FN and Geert Wilders' Dutch Freedom Party (PVV). Yet in turn, others like Germany's Alternative für Deutschland (AfD) distances itself from UKIP, saying its views are too extreme.

Paradoxically FN seems to garner support in France among immigrants, who might vote for this party. Le Pen's rhetoric is based on using policies of the left - like protectionism - to wrest sympathy from left-wing parties. She reckons the FN will be able to ally with the Dutch PVV as well as nationalist parties in Austria, Italy, Belgium and Sweden.

The question is whether the tensions over anti-EU policies and the traditional prejudices between national interests and pan-European populist movements would be an obstacle to any meaningful co-operation between Eurosceptic parties.

