The contemporary separation of powers

Upon the opening of the United Kingdom Supreme Court in October 2009, that court's first president – Lord Phillips of Worth Matravers – noted the symbolic significance of establishing the independence of the country's highest court from Parliament:

This severing of institutional links was certainly decisive, and may come to have a significance that can only be speculated upon in the early stages of the new court's life. But this institutional independence is merely one aspect of the contemporary separation of powers. Understandings of the United Kingdom's unique separation of powers have tended to hold more currency in their emphasis of the ‘pragmatic’ realities of constitutional practice, rather than the assertion of a ‘formal’ doctrinal adherence to a version of separation of powers theory. The bright line distinctions hinted at in Lord Phillips' welcome to the new judicial body have rarely been evident across the spectrum of governmental functions visible in the United Kingdom, nor in its institutional divisions.

In part, at least, these institutional overlaps and lack of functional clarity can be attributed to the fact that our constitution has never been implemented – rather, it has developed, or emerged, over time.