EVERY good disaster movie has a scene in which the characters realise that they are in mortal peril, that the threat they all fear is much closer than anyone had thought. The shark is in the water, the caller is in the house, the virus is airborne. Footage of a Cabinet meeting on July 5—taken before the resignations of Rishi Sunak, the chancellor of the exchequer, and Sajid Javid, the health secretary—provided an equivalent moment in Westminster’s horror show. The faces of Britain’s most senior politicians are ashen, the mood is palpably grim. A deadly toxin menaces them and their party, and it is chairing the meeting.

The fact that Boris Johnson is a serial liar and lacks the self-discipline to apply himself to hard problems is well-known. One of those grey-faced Cabinet ministers, Michael Gove, said that Johnson was not up to the task of leadership back in 2016, and his verdict then was spot-on. But the extent to which he poisons the reputations of those he comes into contact with is striking. This toxicity is not just a personal characteristic. It also says something important about the political system he sits atop.

Take a moment to consider some of the people tarnished by exposure to the prime minister. Many are politicians, sent out to defend Johnson’s integrity only to find their own impugned as a result. The most recent scandal turns on the extent to which the prime minister knew about the reputation of Chris Pincher, who resigned as deputy chief whip on June 30 after being accused of drunkenly groping two men. Ministers like Will Quince dutifully told interviewers that Johnson was not aware of prior allegations about Pincher’s behaviour. Quince quickly found out that this was untrue, and resigned. At best such politicians look like idiots, at worst as slippery as their boss.