Polite or cutting question? As it’s from Matt Baker, I’m inclined to think it was merely bland small-talk, but I love the ambiguity and Cameron’s initial shock.
Matt Baker: How on earth do you sleep at night?
David Cameron: Horlicks mixed with the tears of disabled children. That usually does the trick.*
http://www.youtube.com/watch?v=VbcACpriZ9s
* Thank you to the person whose comment on Youtube I have paraphrased/nicked.