It has survived thus far because good men have generally not done nothing when push came to shove, as in the current Green farrago. However, it is very vulnerable to the growing jobsworth culture of forms and process that has put more power in the hands of those who either don't understand, or see it (as many of the brain-cleansed senior plod now seem to) as an opportunity for a spot of front line social engineering.
Gorbals' replacement of a very well-attuned toff by a mediocre but compliant civil servant is a good example of how such a system can be perverted. And it's good to note that HM's instincts were perfectly sound, as usual.
However, this perverse but precious nature of Britishness is something even a generally socially dysfunctional character like Broon has started to wake up and realise is something that doesn't necessary instill itself by osmosis once a person steps across the border.
The big fix for this increasingly unnerving state of unBritishness is going to be tricky. In the short term it is best solved by dumping Baron Mandelson's puppet government in a skip, and clearing up the worst of the mess before we can usefully move forward.
Al Murray for PM?