Back patting

A group of unnamed sycophants burst into spontaneous applause during David Cameron's press conference earlier.

Clapping is not a sound usually heard at these events.

More common is a hack's guffaw or a press officer's grinding teeth.

It was unclear from watching it on TV who the culprits were, and a Tory press officer I spoke to was none the wiser.

However, she assured me that no one was holding placards reading "applause now".