I know David Cameron. Not well, but I know him. He is not, as Boris Johnson is bizarrely now suggesting, proud of Brexit. He regrets the result of the referendum very much but he stoutly maintains that it was right to ask the voters, even though their reply was not the one he wanted. I have heard him refer to Conservative MPs who are fighting for a soft Brexit as “heroes”.

In no sense, then, is Mr Cameron sympathetic to anything Mr Johnson has been trying to achieve. Any such claim will infuriate him. I wonder if a desperate Mr Johnson is taking leave of his political senses.

There’s an old and doubtless apocryphal cartoon featuring a group of explorers who, cut off from their