The Conservative Party is suffering something like a nervous breakdown. To watch the Tories in the Commons is to watch a group that has lost much of its self discipline. Members openly insult each other, the leader has only just survived a vote of confidence, and the pro-Brexit European Research Group of backbenchers appears to have its own whipping system and policy platform.

The idea of a formal split cannot be dismissed; indeed in parliamentary terms it already seems far advanced. When the ERG announced that its members — who, let’s not forget, are all Conservative members of parliament — had decided after much consideration not to support Labour in a vote of confidence in Theresa May, this counted as news.

When strong and healthy,