Back in 1997, the former minister and famous political diarist Alan Clark identified a potentially fatal flaw in the Conservative party’s leadership system. No, not the controversial membership vote – William Hague did not introduce that until 1998. For Clark, eloquent reactionary that he was, the problem was giving MPs the vote and formal mechanisms to challenge the leader when the old “magic circle” was abolished in the 1960s.

The problem, as Clark saw it, was that it would turn the question of the leadership into a pageant without end. The press would always be able to speculate about a contest, and MPs looking to puff themselves up would have an easy way to do so. Over time, the party’s old norms of internal discipline would, said Clark, be worn away.

A quarter of a century on, events lend credence to his depressing thesis. It was once said of the Conservative party that loyalty was its secret weapon; nobody says that today. In the 1990s, Clark could write of the foolishness of leadership hopefuls who missed their chance, waiting for a better shot at a job that had only fallen vacant a handful of times since the second world war; as it stands, David Cameron was the last Tory leader to remain in post for an entire parliament.

There is surely no disputing that the Conservative party has become a highly unstable institution, and few institutions........

© The Guardian