Scottish political staffers in the corridors of European Parliament’s Altiero Spinelli Building in Brussels must know something the rest of us don’t. They’re telling anyone who will listen that no matter who wins the referendum, the following Monday it will be business as usual: flights are booked, committee work diarised, restaurant tables locked in.

Or perhaps the Euro-Scots are just putting on a brave face. They must know that if the “yes” vote carries the day in the September 18 referendum, everything about their role in the European Union will be up for debate. There will be no going back.

Both sides agree that an independent Scotland would have to apply for EU membership, a process that can take years. Scottish EU civil servants and Scotland’s eight members of the European Parliament (MEPs) can therefore expect to spend time in a no-man’s land while the EU decides what to do with them.

The EU could end this uncertainty in a flash. The European Commission (the EU’s executive) could announce measures to manage the transition to ensure that, for example, Scots in EU countries on United Kingdom passports would be allowed to stay.

But the EC has been on the receiving end of British outrage often enough to know when to keep its mouth shut. And this is one such occasion, according to the EC’s unflappable Danish spokeswoman, Pia Ahrenkilde-Hansen. “We do not feel, at this time, in the middle of the final stages of the campaign, that we should interfere with what is an internal, democratic process,” she said.

The caution might have something to do with the fact that the last time EC President Jose Manuel Barroso tackled the issue, it didn’t end well. The former Portuguese prime minister told the BBC it was “extremely difficult, if not impossible”, for an independent Scotland to be welcomed back into the EU.

His comments may have gone down well in Westminster and Madrid — Spain is particularly concerned that Scottish independence would set a precedent for Catalan separatists. But the remarks sparked a backlash in Scotland, and since then the EC has stuck to a strict “no comment” policy.

The stonewalling has been driving the normally placid EU media corps into a frenzy. This week, Ahrenkilde-Hansen was heckled and derided by journalists, with one reporter describing her approach as “a bizarre way to see the democratic process”.

Clearly, the EU has given some thought to a transition plan for an independent Scotland: the alternative would be a posse of parliamentary security guards rounding up Scottish illegals. Yet by pretending it hasn’t, the EC is adding to the uncertainty over an independent Scotland’s future in the EU — something that plays into the hands of the unionists.

“It is conceivable that, unless we choose to change our constitutional circumstances this coming September, we could be dragged out of the European Union against our will.”

Yet even as EU leaders are claiming the issue has nothing to do with them, Scotland’s First Minister Alex Salmond is arguing the opposite. Speaking in Belgium in April, he said independence might actually prove to be Scotland’s best chance of remaining in the EU. His logic was simple. Unlike their English counterparts, Scots are comparatively positive about EU membership (two-to-one in favour). However, with the British government committed to holding a referendum on EU membership in 2017, a UK exit from the EU is a real prospect.

“People in Scotland would almost certainly vote to stay in the EU, but the result for the UK as a whole is much more doubtful,” Salmond said. “Because Scotland makes up just over 8% of the UK population, it is conceivable that, unless we choose to change our constitutional circumstances this coming September, we could be dragged out of the European Union against our will.”

That may be. But Scottish Labour MEP Catherine Stihler told me that leaving the EU in the hope of rejoining was a big gamble. “We are part of the United Kingdom at the moment; we are part of the European Union at the moment,” she said. “The nationalists risk both of these.”

And whatever you think of Barroso, at least he had his finger on the pulse of Europe’s national leaders. So, when he described Scotland’s accession as “virtually impossible”, you can bet he wasn’t freestyling. Just because you don’t need a passport to cross most EU borders doesn’t mean you can mess with state sovereignty.