In 2012 and 2013, two sessions will take place during the same week in October in order to save one trip to the French city.
Yesterday's (9 March) vote saw 357 MEPs vote in favour of the move, while 253 voted against amid 40 abstentions.
Continuous travelling between Strasbourg (the European Parliament's official seat) and Brussels (its de facto seat) has long been a bone of contention among MEPs.
Traditionally, Europhiles and nationals of the EU's older member states have ranked among the twin-seat Parliament's biggest supporters, while Eurosceptic MEPs and those from newer member states complain about the cost and negative environmental impact of the EU's so-called monthly 'travelling circus'.
Minds are so divided on the issue that MEPs regularly find themselves at loggerheads. Indeed, prior to the vote, UK Conservative MEP Martin Callanan (European Conservatives & Reformists) accused German member Bernd Posselt (European People's Party) of having lost touch with reality in his attempts to "defend the indefensible," as he described the monthly decampment of 736 MEPs and their staff from Belgium to France.
Opening a Pandora's Box?
This is "the beginning of the end for Strasbourg," Callanan told EurActiv. According to the Conservative MEP, the parliamentary authorities and President Jerzy Buzek allowed the vote to go ahead because they saw it as legitimate, despite the lobbying of some MEPs against it.
German MEPs are renowned for wanting to save EU money, so "Posselt is being positively anti-Germanic" in wanting to keep Strasbourg, said Callanan.
He explained that behind the vote, which was taken by secret ballot, was a cross-party, cross-national effort. "This was not just the Tories," Callanan observed.
Violation of the Treaty?
Posselt, meanwhile, called into question the accuracy of figures that are regularly cited in attacks on the two-seat system. In an email sent to MEP colleagues, seen by EurActiv, he described one figure that was circulating, €150m, as "fantasy". "Experts speak of €50-70 million," he said, blaming the size of that figure on a lack of organisation rather than on the Strasbourg seat itself.
After the motion had passed and the decision to merge two sessions into one in October 2012 and October 2013 had been taken, Posselt issued a statement claiming that the vote was "partly illegal".
The concentration of two regular Strasbourg plenaries in just one week "is a clear violation of the Treaty, which speaks of twelve monthly plenary sessions".
"According to the Treaty, Strasbourg is not the second seat, but the only seat of the European Parliament, and whoever wants to save session time, money and CO2 has to concentrate work at the Alsatian metropolis and not[in Brussels]," Posselt said in his statement.
Many French MEPs, however, want to see the decision challenged in court. They are calling on the French government to assess whether it is possible to challenge the vote at the European Court of Justice in a bid to see it declared contrary to the EU Treaties.