As television interviews go it was of the ‘abandon ship’ variety rather than providing sturdy reassurance from the bridge. Sir Keir Starmer, from a torpedo-damaged Downing Street, gave a less than serene account of himself.

Message to wardroom orderly: fresh underpants for the admiral, please.

Sir Keir was asked by Channel 4’s political editor, Gary Gibbon, about Lord Mandelson’s immolation as ambassador to Washington DC. Sir Keir likes to present himself the greatest prosecutor since Hartley Shawcross but this interview owed more to the interrogation of an accomplice in a bungled bank robbery. It wasn’t his fault, guv. He hadn’t known nuffink.

The patter sounded, if a former theatre critic might be permitted to observe, overly rehearsed. To make lines persuasive, an actor must somehow convey spontaneity. In this Sir Keir failed.

Sitting sideways, he spoke fast, with leaden emphasis. The right hand was waved in the air like a ping-pong bat. His left eyeball throbbed, its white expanding. You normally only get that in horror films, when the heroine is about to be knifed in the shower.