The shape of the Brexit fix that Boris Johnson wants from the EU’s 27 leaders is now clear. Here it is:

In place of the dreaded backstop – that insurance policy for keeping open the border on the island of Ireland hated by most Tory Brexiters and Northern Ireland’s DUP – Johnson is suggesting:

a) A unified single market for agriculture between Northern Ireland and the Republic (a single set of what are known are sanitary and phytosanitary rules), so that cross border flows of livestock and food is not hindered;

b) Customs and limited unintrusive goods standards checks on the island but away from the border itself;

c) No customs...