It's the way you tell 'em, as Ed Miliband found out when his perfectly good joke bombed

Ed Miliband had a well scripted joke to use at Prime Minister's Questions this week. It went: "Our sympathy is with the Deputy Prime Minister. His partner goes on a business trip and he is waiting by the phone, but he hears nothing until a rambling phone call at 4am confessing to a terrible mistake."

It should have had them rolling in the aisles, but it bombed. His audience could not even hear it properly because Tory MPs were still laughing so raucously at the way David Cameron had turned his severely tested partnership with Nick Clegg into a one-liner: "It's not that bad – it's not like we're brothers."

The Miliband joke, which may have been a last contribution from his gag writer Ayesha Hazarika, who is moving to work for Harriet Harman, looks better on paper, but Miliband lacks that gift that Cameron has of being able to deliver a rehearsed joke as if he has just thought of it.

Almost all front rank politicians feel the need to tell jokes, though very few are actually any good at it. Through history, nearly all the best have been sharp put downs, such as the description of Clement Attlee, attributed to Winston Churchill, as "a modest man with much to be modest about", or Denis Healey's remark that being attacked by the dogged Sir Geoffrey Howe was like "being savaged by a dead sheep".

One of the funniest extended routines ever performed by a professional politician was when Margaret Thatcher ridiculed the Liberal Democrats in a routine based on a Monty Python sketch. What was so funny was that Mrs Thatcher had no idea what the joke was, and delivered it like a strident political statement.

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* "Dinner ladies earn less in a week than Osborne spends on his ski holiday," was Miliband's jibe on the day of public sector strikes, which baffled many as a statement of the obvious. It is presumed he meant to say year.

* After allegations about George Osborne's youthful encounters with a dominatrix surfaced in the press, Miliband compared his (alleged) experiences to his economic obstinacy: "The Chancellor has lashed himself to the mast...not for the first time, perhaps."

* Perhaps Ed's poorest one-liner was in response to suggestions that he had an operation on his nose to change the nasal tone of his voice: "My nose job July 27. They called it 'Ed Nose Day'."