The problem with this kind of thing is that most people don't have a clear opinion on most things until they're asked to give one. It may well be that 52% of Labour and undecided voters in Bassetlaw say that they want the leave the EU when asked, but will that be at the forefront of their minds when they vote in next year's election?
We could not have work permits for EU workers and stay in the EU.
Of course we could....We are a sovereign nation. There would be consequences and we would have to tough-out (ignore) the annoyance of various EU bodies. The EU would in the medium term have to decide whether to expel us and loose a shed-load of cash or tolerate and snipe at us. In any case we would still have had some years of full work permit control. Win-Win situation. Mann is right to press the point.