There are stories that shimmer for a few days then dissolve until their next scheduled appearance in the calendar of unlikely news. For example: that alcohol is actually good for you; water has been found on Mars; and Boris Johnson is back in the running for the Tory leadership.

Mr Johnson achieves the unlikely double of being both irrepressible and unsustainable. He is destined to discover that he never was, after all, toying with destiny: destiny was toying with him. Like Sisyphus he pushes his rock up the mountain. And still it rolls down again.

Thus it was we opened newspapers this week to read that a survey by the ConservativeHome website charts Boris’s triumphant return to the bosom and affections of Tory activists. After