I doubt that the single market is all that is lost.  Remember that the European project began as an economic solution to a political problem.  The integration of European coal and steel markets was to make war unthinkable between European states.

Moreover, intra-EU trade is as often in components as in finished products.  Supply chains cross national boundaries.  Restablish border controls and tarriffs and you wreak havoc on the whole economy built upon the assumption of open borders.

And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg