The home of the European Parliament is in Brussels, close to key EU institutions such as the European Commission and the European Council. For historic reasons, however, parliamentarians are obliged to hold 12 plenary sessions a year in a second parliamentary building in city of Strasbourg in eastern France.

That means that for one week of every month, all 750 members of the European Parliament (MEPs), plus thousands of staff, have to travel down to Strasbourg by plane, train or car. By road it's a distance of over 430 kilometers, or more than four hours - a half-day's lost work.

The cost of running the parallel operation in Strasbourg is estimated at 170-200 million euros a year ($217-255 million), more than ten percent of the parliament's entire annual budget. Then there's the environmental aspect of the Strasbourg circus. Campaigners point out that an estimated 19,000 tons of CO2 emissions are released due to these 12 sessions.

Citizens' movement

The court ruling comes at a time when austerity cuts in many European countries are forcing ordinary people to make sacrifices in their everyday lives. More than 1.2 million EU citizens have signed a petition calling for a single seat in Brussels. Many are asking why something wasn't done long ago to curb spending on Strasbourg.

"The problem is that the European Parliament actually doesn't have a say on the matter," said Alexander Alvaro, a German liberal MEP and co-chair of the Single Seat campaign. "If it [did], I think it would have been changed a long, long time ago, as we also see in the voting figures."

Momentum for change is building among MEPs, most of whom back the idea of holding all parliamentary business under one roof. In a vote in European Parliament on October 23, 74 percent of MEPs voted yes to prepare a "roadmap for a single seat." Just 21 percent voted against the motion, most of them French.

Legal issues

The problem for those who want to get rid of the 12 Strasbourg sessions is that it's enshrined in EU treaties, a fact that renders change extremely difficult.

"The treaties can only be changed by member states by unanimity and we know that France is blocking this procedure so far, but I believe they also see the signs on the wall that this has to change now," Alvaro said.

But Nathalie Griesbeck is having none of it. Like Alvaro, she's a member of the liberal alliance, but on the subject of Strasbourg, the two politicians hardly see eye to eye.

"The treaties laid down that the most important institutions in the European Union should be spread among the member states," said the French MEP. "And France obtained the right to host the European Parliament in Strasbourg. So that's a very important legal reason."

Griesbeck refuses to countenance the idea of treaty change: "As a member of the European Parliament, I think we've got enough to worry about - and better things to think about - than using all our energy to change the treaties."

While the issue has a long history, it was European Parliament's decision to hold two separate sessions in a single week in October - the first of a so-called "super session" - that brough the issue to the doorstep of the European Court of Justice in Luxembourg.

On Friday, December 13, the court ruled that holding fewer than 12 plenary sessions a year in Strasbourg was illegal under existing EU laws.

Historic city

It's impossible to dispute that Strasbourg is a beautiful city. Its historic center, with its beautiful timber buildings, quaint streets and towering Gothic Cathedral, has been declared a UNESCO world heritage site.

Those who own businesses in Strasbourg were - and to some extent still are - deeply concerned about the potential loss of revenues from the loss of the parliament. Hotels and restaurants are routinely booked when the politicians, lobbyists and journalists are in town.

The campaigners have put forward a number of ideas for ways to avoid harming the local economy. Alexander Alvaro proposes the creation of an elite European university.

"If you had a postgraduate university here for European and worldwide students - high-quality, comparable to something like MIT, Harvard, Stanford - we would actually create an environment where the economic benefit wouldn't be reduced to 12 weeks a year. You would have events going on throughout the whole year, people coming, visiting. The quality of life would get better," he said. "So I believe France is quite short-sighted not to see these opportunities."

But it seems that, given the major hurdles involved, even the most optimistic campaigners don't expect the situation to change within the next five years. In the meantime, the legal wrangling is providing a healthy income for lawyers.