Only a written constitution can prevent further abuses of power
Almost alone in the democratic world, we British have no written constitution protecting our basic civil and political rights. We have no charter defining the scope of the powers of the legislative, executive and judicial branches of government. Where parliament remains passive, the government, clothed in ancient monarchical authority, exercises unbridled prerogative powers - to wage war, to make binding treaties, to control the civil service and to issue or withhold passports.
Post Hutton and Butler, provided that ministers act in "good faith", ministerial responsibility for gross errors of judgment is written in water - except at election time.
There was another example of the abuse of prerogative powers when the government announced its decision not to allow British citizens to take complaints of breaches of the UN covenant on civil and political rights to the UN human rights committee. We are alone in the European Union in this respect. What the government dislikes about giving us the right of petition is that it would bring into play the covenant's guarantee of equality without discrimination - a guarantee that is enshrined in the written constitutions of the other European states. The government is judge in its own cause, and we citizens can do nothing about this denial of a basic constitutional right except to campaign for better government.
Ever since the American and French revolutions, British political leaders have rejected the idea of entrenching fundamental rights in a supreme constitution. For 40 years British governments have exported written constitutions to new democracies across the former empire while opposing any proposal to place themselves under similar constraints at home.
The two principles of the unwritten Victorian constitution under which we are governed are parliamentary supremacy and the rule of law. But parliamentary supremacy usually means executive domination. As for the role of the independent judiciary, it is essential in ensuring that governments do not act lawlessly or use their powers to excess, but the courts are subordinate to an executive-dominated parliament: lions under the throne, and even their independence can be undermined by political interference.
For British governments, power is delightful, and absolute power is absolutely delightful. Parliament may pass a human rights act, but a future parliament could repeal or emasculate it. In 1968, parliament enacted emergency legislation to deprive 200,000 British Asian passport holders fleeing from racial persecution in East Africa of their right to enter and live in their country of citizenship. The statute was racially motivated, but there was no remedy in our courts because parliament can use its law-making powers as it (or the government) pleases. Recently, the government came close to persuading a supine parliament to pass a law depriving vulnerable asylum-seekers of access to judicial review to challenge abuses of Home Office powers. It was only the threat of defeat in the Lords that induced them to abandon this measure.