AP Photo

As David Cameron entered the Commons at the end of a morning that began with his speech on Europe, his backbenchers did something they rarely do these days. They cheered him to the echo. Moments earlier the Conservative chairman, Grant Shapps, had announced on TV that the Europe speech had united the party. The sight of so many delighted Tory MPs, many of whom have become minor political celebrities by making the prime minister's life miserable, seemed to suggest Shapps was right.