Britain’s new opposition leader today faces his first big parliamentary challenge at the weekly session of questions to the prime minister, following a dire first few days on the job. Jeremy Corbyn’s choice of shadow chancellor—John McDonnell, perhaps the only Labour MP more left-wing than he is—incensed party moderates. A string of prominent Blairites, including two of Mr Corbyn’s leadership rivals, refused to serve in his shadow cabinet; then he seemingly forgot to give any senior jobs to women (but hurriedly offered them plenty of lesser ones). He needlessly muddled his party’s stance on the Brexit referendum. And at a military memorial service he looked grumpy and scruffy, refusing to sing the national anthem. The Tories are delighted by their unelectable, ill-advised rival and the divided state of his party. But as prime minister, David Cameron might seem arrogant to attack him personally; better to lambast his republican and anti-Western views.