The Commission has based Eurocrats for the past 40 years at a building owned by the insurance company AXA Belgium.
But the office block - known as the JECL building which provides office space for some 1,500 Commission staff including translators and administrators - has been at the heart of a dispute since 2001.
Now, AXA has had enough and is ordering the bureaucrats to leave by the end of the year.
"In the last five years, there has been endless talk about redeveloping the site into a conference and office centre for the Commission to use," says a source.
"But they keep insisting the rent AXA is asking for is vastly over the current market rates, and far more than they can afford. Now AXA has had enough and decided to call the whole thing off."
Mandelson and his colleagues on the Commission are upset by this, and insist they need at least six months to rehouse their staff. A spokesman for the Commission insists that "negotiations are still ongoing."
Unsurprisingly, perhaps, UKIP is taking great delight in the situation. "The building is probably in desperate need of renovation, considering the amount of dead wood it shelters," chuckles their MEP Nigel Farage.
* Most of Jeremy Clarkson's controversial comments are well-aimed public shots at carefully chosen enemies. But today, the Top Gear presenter finds himself at the receiving end of some unwanted publicity after an outburst against a presenter on the local Manchester radio station, Galaxy.
As part of the tour to promote his Christmas stocking-filler DVD, Clarkson was last week invited on to Wes Butters' breakfast show, but after broadcasting his segment, believed that the DVD hadn't received sufficient publicity.
Turning to one of his associates, Clarkson said: "They didn't even mention it. There's no point [in being here] if they are just sitting wanting me to do stupid phone calls. Let's go."
What "Motormouth" didn't realise is that his microphone was still on, and his words were broadcast to the station's many listeners.
"I couldn't believe what I was hearing," counters Butters. "I wouldn't mind, but we did speak about his DVD and it's on tape. I'll still be watching Top Gear, though."
* It's official. BBC Radio 4's rural soap opera, The Archers, is employing a deliberate strategy to attract new listeners.
"Let's not be too idealistic about it," says Tim Bentinck, who plays David Archer.
"It's got to keep going for the good of the country. So you have Dross the band, infidelity, drugs, inappropriate sexual relations. We are encouraged to foster debate."
In an interview with The Field magazine, Bentinck goes on to explain the show is also engaging with current rural affairs.
"But I'm not the expert," he says, modestly. "Any farmer reading about some bloody actor who thinks he knows about farming because he's done it on the radio would say: 'Shut up, you're talking rubbish.'"
Unless, that is, the farmer had old-fashioned respect for the aristocracy: the Islington-inhabiting leftish actor is also the 12th Earl of Portland.
* David Cameron's victory speech kicked off with a promise to get more women involved in Tory politics. It's ruffled feathers among her friends, therefore, that the capable MP Julie Kirkbride has - so far - been overlooked for a role on his front bench.
"There have been mutterings that it is because Julie supported David Davis," says one chum.
"But that doesn't really hold any water because her own husband, Andrew Mackay, was a Davis supporter and has been given a plum advisory role. Could it be because Julie's a bit 'council flat' for Cameron's lot to deal with?"
From very much the right side of the tracks comes Zac Goldsmith. The millionaire ecologist has been asked to help guide the party on green issues, and is a prospective parliamentary candidate.
* Ain't life grand in the highest diplomatic circles. When Francis Campbell, the new young ambassador to the Holy See, arrived in Rome, it was by Ryanair.
The decision to use the budget airline is a clever one in terms of keeping costs down - but it has caused difficulties in other areas.
"Francis has been worrying about how he's going to get his ambassador's sword out there," says a friend. "He was not allowed to take it on the plane because it might be used in a hijacking, and they don't want it in the hold."
As a result, His Excellency is attempting to find a diplomatic bag large enough to conceal the weapon.
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