Cameron will pay a price for allowing Euro sceptic ministers to vote against him if and when he calls the referendum to endorse whatever deal he strikes with the EU. It is one thing for Corbyn in opposition to allow dissent in the shadow cabinet, but it is quite another for the prime minister to put up with disunity in the real one. People expect the government to lead; that is what they pay for. One which cannot make up its mind on an issue as profound as whether to walk out of the EU will never recover its authority. Labour never regained its composure after Wilson let the cabinet go its own way at the last referendum. Cameron will have the same problem. He can only avoid it by reshuffling his cabinet after he gets whatever deal he can and before he calls the referendum. It is imperative that he goes to the country with his government behind him. All of them.