Power cut stops work at most EU buildings

The parliament was the most seriously affected - a handful of officials were stuck in lifts for up to 30 minutes and all MEPs and staff were told to go home for the day.

"It was not evacuated in the sense of an emergency but we asked people to go home because normal activity is impossible. People could go back to their offices to get their coats and so on. It was very calm", spokesman Jaime Duch said.

In the commission, phones kept working but lifts, lights and computers went off. Emergency lighting in fire escapes and a blackout-proof email system - called Noah - for certain staff with smartphones kicked in.

The commission told staff to go home at 4.30pm. But a few minutes later, the lights went on, meaning the hour's extra leave was cancelled. Commission spokesman Antony Gravili told EUobserver: "People can get back to work now, it's still just 4:30." It is unclear how many staff made the u-turn back to their desks.

The EU Council, which has a greater number of back-up generators due to its work with EU security and defence missions, saw the least disruption.

"Everybody is still here ... It's like the good old times. I am rejoicing in the pleasure of working on paper in the beautiful sunlight streaming through my window," one Council official remarked.

Iris Fostiez, a spokeswoman for Sibelga, the Belgian firm that supplies electricity in the EU district, said the fault was caused by a fire in a transformer station situated below the gardens of the Representation of the Free State of Bavaria to the European Union.

"There was a lot of smoke, and because it is an underground chamber, it was hard to get the smoke out. The firemen had to get special breathing and ventilation equipment so that the technicians could do their work", she explained.

The cause of the fire is unknown but Sibelga does not suspect foul play.