I’m not buying this line of argument. Johnson knew, as everybody in the Conservative Party knew, that the Brexit referendum was about heading off the (over-stated) electoral threat from UKIP and simultaneously dealing with a fringe group of MPs in the party who were a distraction and wouldn’t shut up. Nobody, Johnson included, thought the country would actually vote for it. There was never going to be a White Paper because nobody sensible could think of anything to put in it. The expectation was that the electorate would sort the Conservative Party’s internal squabbles out for them by decisively rejecting it and all would be well. As an aside, we have the choice of continuing with this failed non-policy or not, and the current government have chosen to continue with it. I would love to see a White Paper laying out the case for staying out of the single market and customs union.