CWU are organising a rally and demo in Witney, Oxfordshire on January 9th. Witney is the Constituency seat of Mr Cameron!
I would suspect that the privatisation of Posties is a live political issue in such a predominantly rural and agricultural area. I'm pretty sure the Post Office does not make any money here from running an universal service.
Interesting to see how they get on.
See source of Cameron's picture and a previous reference to Whitney here.