Various claims have been made but what is the legal reality? 

Its proponents still refuse to confront reality

There are problems with the text but concerns about an indefinite Northern Ireland backstop are overegged 

State aid rules stop governments giving unfair handouts. Britain has pledged to keep them after Brexit, but how to build a regime that works?

Departure from Europe throws up yet another fundamental constitutional question

Parliament should have a greater role in negotiations with Europe and third countries

Trade remedies are the heavy artillery in a trade war. But will Britain have them in place by the time it leaves Europe?