“There is a comic element to sending submarines to sea without missiles,” began the prime minister’s answer.
It came in response to Tory MP Karl McCartney’s suggestion Jeremy Corbyn’s defence policy had been “inspired by the Beatles’ Yellow Submarine”.
It’s unlikely the Fab Four would have anticipated their songs being used by politicians stressing the significance of nuclear deterrence.
But that’s how the script went…
Mr McCartney – not believed to be any relation of Paul’s – managed to cram not one, not two, but three Beatles references into his question.
After the Yellow Submarine gag he crowed: “It shows while the members opposite Twist and Shout, their current leader certainly needs Help.”
The question was greeted with raucous cheers and guffaws of laughter, before Mr Cameron congratulated his MP on “your ingenious question”.
Pause to remember the topic under discussion was nuclear weaponry….
The PM was quick to clarify “in fact it is absolutely serious” because the deterrent had been a “key part” of the country’s defence.
But it didn’t stop him delighting in a Beatles reference of his own.
“All I can say when it comes to Beatles songs (is) I suspect the leader of the opposition prefers Back in the USSR,” he quipped.