Surely that's unconstitutional

I read today of a great wailing and gnashing of teeth as Members of Parliament are flung to the dogs by their parties for doing what those parties had encouraged them, actively or passively, to do. In the midst of it all was Harriet Harman wielding Excalibur fearlessly and snicking heads off left and right. Like an avenging angel she has descended upon the unworthy denizens of the Houses of Parliament to smite them and tell them how it's going to be.

There's no flippin flipping, no furniture, no cleaning, no stamp duty, a cap on mortgages, and external regulation.

Hang on...

Parliament answerable to external regulation without a written constitution? It would be questionable in the Scottish system where sovereignty rests with the people, under the principle of Parliamentary sovereignty as the Westminster place is supposed to be, it's just daft. Since the philosophy underpinning Westminster is that Parliament is sovereign - even to the extent that it cannot be bound by a previous incarnation of itself - how can any external regulator dare to do anything about it? If Parliament submits to external regulation it is no longer master of its own destiny and therefore, arguably, no longer sovereign.

The bigger point, though, is why would we feel that it is appropriate to trust these people to run our economy (which is still down the pan) if they can't run their own expenses system and police themselves in an open and transparent manner? It seems more like being desperate to shift the blame than sort out the problem.