Remainers couldn't believe their luck on hearing that a new civil service report couldn't find any an outcome to the Brexit talks that would be better for the economy than staying in the European Union. And that the press had a copy.

The leak prompted MPs to demand its release in full, which Theresa May has had to agree to do because she knew –lacking her own majority in the Commons - that it couldn't keep them at bay for long. Remainers are jubilant over the "very good news" (in Chuka Umunna's words), with Sir Keir Starmer declaring on Twitter with a swagger that the analysis needs to come out at latest by the end of this week. 

The Remainer excitement over the document, titled “EU Exit Analysis – Cross Whitehall Briefing”, means it is inevitable they will be quoting it chapter and verse to support their arguments.

Why should the Government persist with negotiating a comprehensive free trade...