I know I’ve upset Edgbaston MP Gisela Stuart a few times by calling her a euro-sceptic.

She doesn’t like it. She’s not a sceptic, she says, just a realist.

This time, she’s gone a bit further than mere scepticism and suggested that the UK might one day have to leave the EU entirely.

Heresy! As she says, to hold such an opinion is seen as a sign of madness within the three major parties. Even those Tory backbenchers currently giving the Prime Minister a hard time over Europe tend to demand a referendum on membership without actually stating that they would vote to leave the EU if such a referendum took place.

But Mrs Stuart, a Labour MP, does have a point. The EU is changing whether we like it or not, and changing in a way which leaves the UK on the outside. Perhaps we need to face up to that.

The crisis in the eurozone appears to be leading to a consensus that mere currency union is not enough. If eurozone members want the euro to work – and they do – then they will require full fiscal union, meaning shared decisions on tax and spending.

It’s going to become increasingly hard to insist that we are full and committed members of the European Union who happen to be outside the eurozone. The eurozone isn’t an optional add-on – it’s the club that matters, and you’re either in it or you’re not.

Those European countries who are excluded will have the option of working towards membership. Poland and the Czech Republic are doing that right now, for example (sometimes in the face of domestic opposition).

But the UK probably won’t go down that road. We could do. It would make sense to consider, seriously, the idea of whole-heartedly joining the European project. But we’ll probably decide against it.

So what happens then? Do we continue to insist that we’re part of the club, and that the other countries aren’t allowed to press ahead with their plans without our permission?

Or would it make sense to start thinking about ways we can continue trading with our European partners without being a roadblock on their hopes and ambitions?