The European project depends, far more than is generally appreciated, on a sense of inevitability. Voters might not care very much for the constant transfers of power to the EU but, as long as they believe that they can’t be stopped, they put up with them. The phenomenon is known in Brussels as the “occupied field doctrine”: once the EU has acted in any area of policy, its jurisdiction in that area is guaranteed in perpetuity.

Repealing a goodly chunk of Schengen would, of course, shatter that doctrine. People might start demanding the return of all sorts of powers. Why should the EU run agriculture given the disastrous mess it has made of the CAP? Or fisheries? Or monetary policy?

Daniel Hannan on his blog April 26th, 2011