John McDonnell has continued his showstopping run at the Edinburgh Fringe Festival with yet another outburst, this time saying that he’ll send Corbyn to Buckingham Palace to tell the Queen “we’re taking over” if Boris loses a confidence vote. While some of the responses decrying it as a full-on coup may be a little over the top, given McDonnell’s willingness to invent retrospective laws to imprison his political opponents it’s not an entirely innocent threat either. Once a revolutionary Marxist, always a revolutionary Marxist…

McDonnell’s key problem is that he does not yet have the ability to change the laws, he and Corbyn are very much limited by both the Fixed Term Parliament Act, and the fact that there is not a majority of MPs in Parliament who would be willing to support him as Prime Minister, even temporarily. The Lib Dems again ruled out propping him up yesterday, and there are plenty in his own party who privately do not want to see him in No 10. How long their principled opposition would last when they got a sniff of power might be another matter…

Conversely, McDonnell’s refusal to back any caretaker Prime Minister who isn’t Corbyn makes the arithmetic impossible for any of the other hopelessly optimistic contenders, from Hilary Benn to Heidi Allen. A week into August and it’s looking like delusional Remainer fantasising about who could lead a ‘Government of National Unity’ is going to be the theme of this year’s silly season…