Herr Barnier has been at it again. This time his shrill demands for money are accompanied by threats to 'shake the tree' to force businesses to relocate from the UK to the EU. This, of course, is a delusion common amongst unelected bureaucrats and petty demagogues who don't understand quite how business makes decisions. It is, however, revealing of Herr Barnier's attitude - and a taste of what we can expect after Brexit.
If the EU is planning how to discriminate against firms headquartered in the UK - even those trading with the EU on WTO terms - it is pretty certain that those measures will be implemented anyway post-Brexit. They will be faced with a nation that has two key weapons in her armoury - corporate tax rates, and state aid. When no longer constrained after Brexit from using these tools, the UK can also apply reciprocal constraints against EU firms, excluding them for example from bidding for government work and so on. A mixture of economic liberalism and targeted protectionism.
The fact is that the EU are quite desperate for British money. They will beg and whine and try all sorts of blackmail in order to force an undertaking from us. Our tactic must be quite clear; no trade deal, no money. And if we need to write-in clauses constraining Herr Barnier's tree shaking, that's useful to know.