David Miliband is reading a Shakespearean sonnet to us at the Globe theatre on London’s south bank. All the world’s a stage for the former foreign secretary, who now runs the International Rescue Committee, the humanitarian aid NGO, in New York. He goes to Oscars parties and has dinner with George Clooney, but he still misses Britain and takes Marmite and PG Tips to America with him. “London is the great city of the world,” he says. “Of course I’ll come back. It’s my home. I’m British.”

Some centrists see Tony Blair’s former policy chief, who was beaten to the Labour leadership by his brother, Ed, as the “king over the water” who will one day return to save the party or set up a