The Guardian posts an article: Bribe your way to the front of the queue in Britain and India
Apparently first class passengers in the UK get undeserved perks from their government much like those in the US. See previous post. In this case it is queue-jumping the immigration line rather than queue jumping the security line. I don't know which is worse. Both are appallingly inequitable and should not be supported by government.
The other thing to note is that this is quite un-British, where the people (or at least the non-elites) are taught how to queue. Queueing is something the British excel at due to their extensive practice in the matter, it would be a shame to see them lose their competitive advantage in this arena.