The current dramatic interaction between the Government, Parliament and the courts means that we are witnessing one of those formative moments in the evolution of our constitution of which there have been many over the course of centuries. The attention that is paid to the checks and balances of the US written constitution has tended to overshadow the fact that a much more interesting confusion and separation of powers has been at the heart of the dynamic development of our unwritten constitution.

In the present struggle, the sovereignty of Parliament has been invoked.  Monarchical ambitions have been detected in the executive. The spectre of the politicising of the courts has been raised.  It may be helpful to re-state as calmly as possible the underlying and enduring structure.  You do not have to be Edmund Burke to believe that it is a remarkable achievement of subliminal collective intelligence over the course of fifteen centuries.

The sovereignty of Parliament merely expresses the legal fact that Acts of Parliament override the common-law, and hence are in that sense supreme, subject now to the effect of EU law within UK law. The powers of Parliament are themselves legal powers which the courts respect and assert and protect.  The Bill of Rights of 1689 says that ‘the freedom of speech, and debates or proceedings in parliament, ought not to be impeached or questioned in any court or place outside of parliament’.

There is no particular magic in the term ‘prerogative power’. The few remaining prerogative powers are common-law powers in the sense that they are not conferred by statute, and in the sense that they are powers whose existence and conditions of application are matters to be determined by the courts. They are also common-law powers in the sense that they may be abolished, abridged, supplemented or temporarily superseded by statute.

The whole of our sophisticated system of public law consists in the review by the courts of decisions made by all levels of the executive branch of government in the exercise of legal powers. Of course, the decisions will often have been made on political grounds, but it is the job of the courts to determine the limits of the powers, given that their exercise abridges the legal rights and freedoms of particular citizens, and in some cases the legal rights and freedoms of all citizens.

All of these things are simply manifestations of the principle of the Rule of Law.  It took centuries of struggle to establish the Rule of Law as the ultimate principle of our constitution, so that it could become an ultimate principle of liberal democracies across the world.

Philip Allott is Professor Emeritus of International Public Law at Cambridge University.

(Suggested citation: P. Allott, ‘On the Merits of Constitutional Struggle’, U.K. Const. L. Blog (14th Sept. 2019) (available at https://ukconstitutionallaw.org/)