The audience may have laughed when Gordon Brown compared his two opponents arguing over Europe to "my two boys squabbling at bathtime" – but Nick Clegg wasn't fooled.
The Lib Dem leader quipped (although it was difficult to hear over the laughter): "It's a good line in rehearsal."
Overhead photographs have confirmed Clegg's suspicions were well-founded and Brown's "ad lib" was actually one of several one-liners helpfully written down on the prime minister's cribsheet.
Thankfully, Brown did not use all of them. One, a reference to Who Wants to be a Millionaire, reads "You can phone a friend, you can ask the audience, you can go 50-50 with Nick."
Another, on nuclear disarmament, says: "Oh boy, the Iranians are going to love you, Nick." Can anyone actually imagine Brown saying "Oh boy"?
"Right versus wrong" and "fair versus unfair" are also offered as potential lines of attack on the crib sheet as – ironically – is: "You're offering slogans, not solutions."
