A good day, given so much news, to recall the experimental nature of Brexit - no developed country has put up trade barriers to neighbours so dramatically since 1945. If the UK succeeds free trade and regionalism are overrated. A lot of text books will need revising.

It is quite tricky to have a serious debate on the economics of Brexit given the UK government claims it to be in line with free trade, though that line works outside the UK with only a few.

The global context matters as well, Brexit is part of an anti free trade movement which is obviously evident from President Trump, but the EU is also showing signs of retreat. Expect many future papers on the subject.

I have heard optimistic Brexit projections, which mainly focus on UK services strength combined with winding down manufacturing. I'm not sure this is politically feasible, though its a likely direction of travel.

Anyway, worth bearing in mind that a government putting up internal borders without finding this strange probably isn't fully committed to trade.