First, a health warning. Although it seems unlikely, at any moment it could be announced that (ring the church bells!) something calling itself a Brexit deal has been agreed between British negotiators and the EU. The number of people involved in making the decision required will be so small – Michel Barnier, the leaders of the two major powers in the EU 27, Theresa May and a handful of officials on both sides – that a breakthrough will happen in secret and then be communicated suddenly as breaking news. Then EU leaders can speedily make their travel plans for an emergency summit to sign off on the Withdrawal Agreement and accompanying texts relating to the future relationship.