By Chris Mason
BBC News, Brussels
Part of the ceiling caved in while MEPs were on holiday
The temporary relocation of the European Parliament to Brussels next month from Strasbourg has reignited a row about where it should be based.
An EU official has confirmed to the BBC that the building in the French city cannot be used yet because part of its ceiling has collapsed.
About 200sq m (2,152sq ft) of the ceiling caved in on 7 August. Nobody was in the chamber at the time.
European law obliges the parliament to meet in Strasbourg 12 times a year.
The total annual cost of the Strasbourg shuttle is estimated to be 203m euros (£160m).
Campaigners say moving everything - lock, stock and filing cabinet - the 352km (220 miles) from Brussels to Strasbourg is a ridiculous waste of time and money, and brand it a "travelling circus".
The Green Party says the monthly trips also produce about 20,000 tons of carbon dioxide emissions annually.
But to others basing the European Parliament in Strasbourg is symbolically hugely important.
The city, in Alsace, is on the French-German border - and it is argued this represents the reconciliation of France and Germany after the world wars of the last century.
The former President of the Parliament, Josep Borrell, has said this historical dimension must not be frivolously dismissed.
But those who argue that this is an outdated view are already stepping up their calls for change.
'Hiccup in gravy train'
The Liberal Democrat MEP Chris Davies says the damaged roof in Strasbourg should be seen as a breakthrough. "We should turn catastrophe into opportunity and meet continuously in Brussels," he said, condemning "the nonsense of the Parliament's perpetual momentum".
His views are echoed by Gary Titley, Labour's leader in the European Parliament, and by the UK Independence Party (UKIP).
"This shows the folly of keeping a building which no one uses most of the year," said Mr Titley. "It is time to break with tradition and make Brussels the only seat of the European Parliament."
UKIP leader Nigel Farage said: "This could save an awful lot of money. For a change we won't have the bizarre spectacle of thousands of MEPs and staff trekking from Brussels for no good reason other than to appease the French. This is a hiccup in the gravy train."
Officials in Brussels will be nervous that campaigners will use the plenary session in the Belgian capital to try and prove there is no need for a base in Strasbourg.
France, the current holder of the rotating EU presidency, has pledged to repair the ceiling as quickly as possible - and aims to have it completed for the planned parliamentary session at the end of September.
It is not yet clear why part of the ceiling, built in 1999, collapsed.
The parliament's secretary general, Harald Roemer, said the repair work was very complicated, involving "a completely new suspension technique".