Prime Minister Tony Blair, Chancellor Gordon Brown, and party spin-doctor Alastair Campbell were on a campaign trip this week, heading to the North of England by train, with all the press pack. But suddenly the train came to a complete stop. Blair thought he had better find out what was happening, so went up to the front to speak to the driver.

"The engine’s broken," he reported back to the press pack. "So I’ve set up an inclusive task force to examine the problem." Nothing happens. So Brown goes up to the front, and reports back: "The engine’s still broken, so I’m providing £5b of new spending that will fix engines up and down the country." Still the train doesn’t move. Whereupon Campbell pulls down the window blinds and tells the press: "There. The train’s moving."