I have never seen Gordon Brown naked but, yesterday at PMQs, it felt that way. David Cameron was on the rampage over the Unite strike. Gordon sat there, wearing nothing but a towel, a politician who is funded by Unite. He was next to Harriet Harman, whose husband is a leading figure in Unite. Down the bench were Dougie Alexander (member), Ed Balls (member), John Denham (member), Liam Byrne (member). I could go on.

They were lined up like ducks in a row, all the easier for Dave to shoot. But for the head duck Gordo, it was even worse, for he'd begun the session by admitting he’d been wrong about his defence spending figures. Until yesterday any Gordo retractions at PMQs were, like the dodo, mythical. So this was a once-in-a-lifetime event, like a double rainbow and Halley’s Comet rolled into one. He looked miserable.

“Na na na na na!” cried David Cameron (or something like that). And then, smacking his lips, he turned to the Unite strike. “When you were asked about it, you said, ‘It’s the wrong time’. Can you tell us when is the right time?”

Gordo used his special hushed “Father of the Nation” voice that I think is supposed to show he’s not a bully. “My thoughts are with the customers of British Airways,” he said, as if at a funeral, “and my thoughts also are with those who depend for their jobs on the success of BA.”

I couldn’t help but notice that the towel was shrinking. Dave shouted: “It’s back to the 1970s! We’ve handwringing from a weak Prime Minister while companies go down!”

In response Gordon wrung his hands some more (tricky when holding a towel, however tiny) and said that Dave had tried to talk to unions. Dave dismissed this as “pathetic” (is that better than “weak”?). “Let me ask him again: does he back brave workers who want to cross the picket line?” Gordon said lamely: “I back a resolution to this dispute.”

Dave cried: “Wriggle! Wriggle! It’s a simple question! It’s a question of backbone, it’s a question of judgment, it’s a question of character. Do you back people who want to go to work?”

But it wasn’t a simple question for Gordon who now would not have looked out of place on a nudist beach. “That is why he can’t lead this country,” taunted Dave. “Absolutely no backbone.” I don’t know about backbone but the Prime Minister could certainly do with some clothes.