We've been members of the EEC/EC/EU for forty years now and yet Euroscepticism is rampant in this country. I suspect we will get a referendum on membership sooner rather than later. But if we do then withdrawalists need a clear and consistent answer to the following question:
Which European institutions should the United Kingdom be a member of?
Wikipedia: File:Supranational European Bodies.png.)
The above diagram shows the various European bodies and the precise combinations of memberships. Several points stand out but the big one is that Norway, Switzerland, Turkey and Russia all have different arrangements and the differences between them could be a splintering point.
Daniel Hannan addresses some of this in Switzerland is a more attractive model than Norway, but Britain could do better than either, but Hannan is not the sole voice of Euroscepticism. He claims "Our preferred model – with some adjustments – is Switzerland", but I'm not convinced all Eurosceptics have delved so deeply into this issue. Many just say "Get out of Europe".
Nor is it clear that the UK would automatically become a member of the European Free Trade Association upon leaving the EU. I'm not even sure if our memberships of the European Economic Area or the EU Customs Union are separately applied for or part & parcel of EU membership and would have to be negotiated anew from outside.
And this is crucial in the debate about access to markets and regulations, and ultimately about jobs. If there isn't a firm answer as to just what the state of things would be the day after the UK left the EU then there will be fear, uncertainty and doubt - the very ingredients that boost the status quo in referendums. And membership of the EU is the status quo...