My friend Sir Arthur Whatnot, the psychiatrist, read Jeremy Corbyn’s piece in this morning’s Observer, in which Corbyn called for Mrs May to sack her Foreign Secretary. Arthur and Corbyn are neighbours, and Arthur has written to the Labour leader in great alarm. He slipped me a copy, in confidence.

Dear Jeremy,

No, no, no. Boris Johnson must not be sacked.

Johnson is the ideal Foreign Secretary for our times. What would it do for our robust stance on leaving the EU if we had at the Foreign Office someone who was knowledgeable, dignified and respected on the world stage? He or she would be, in effect, a collaborator, if not a traitor.

Jeremy, we both know that the world Johnson lives in is a wholly imaginary construction, a figment of the puerile, the deluded and the vile. But the dear old sausage seems to believe in it, and wants us all to join him there. Does that make Johnson a colonial throwback as you suggest? No it does not, Jeremy. You need to understand that the man is a New Colonial, a NeoCol.

A NeoCol Britain will not repeat the practice of subjugating the funny natives of those places we call ‘overseas’. In the NeoCols’ view, the non-European ‘overseas’ has been marking time for 40 years, waiting to throw open its markets to our gaudy, hi-tech beads and baubles, and to chop down its forests to grow food for us and so forth. What’s more, the NeoCols promise their favourites stability, Jeremy. The leaders of ‘overseas’ – kings, faux democrats and tyrants – will be able to stash what they leech from their struggling economies snugly in London’s strong and stable tax haven. The Fox-hole as they will call it.

In all this, Jeremy, I have two related professional concerns. The first is for the PM’s state of mind, and the second is for the danger that her psychological collapse poses to you.

First the PM. I cannot imagine Mrs May sacking Johnson, not without a gaff of even greater magnitude than to date. But what if Johnson were to fall under a double-decker bus? (You, as a Londoner, know which bus I have in mind.) Suppose, further, that Mrs May, in an impetuous moment after Sunday matins, appointed to the FO somebody rational, impressed by facts, and diplomatic. (Don’t press me on who on earth that might be, I’m only a humble psychiatrist.) Can you imagine the internal torment that Mrs May would suffer, more even than now; what forces would rage within her?

Secondly, you, Jeremy. You have impressed me in wanting a new type of politics, a less coarse debate, more keyed in to the needs of the population. But are you prepared for tears across the dispatch box at PMQs as Mrs May fights to reconcile the psychotic voices behind her with Britain’s needs? Tears, my boy, that we shed when we cannot resolve the unresolvable. And what a dilemma you might face regarding your reputation among different voting groups in the country if the Prime Minister of the United Kingdom were to ask the Leader of Her Majesty’s Loyal Opposition if he would, please, please, give her a hug.

Your most respectful friend,

Arthur