Reading through the student essays on constitutional law I wrote 50 years ago, I see we were taught that some prerogative powers were absolute. As one rather ancient textbook assured us, ‘there is no means of making the king or his ministers accountable at law for their exercise’. In response, I argued that ministers who exercised prerogative powers were ‘always answerable to parliament and eventually to the electorate’. 

Joshua Rozenberg

Joshua Rozenberg

How times change. Boris Johnson found that the power to prorogue parliament did not allow a suspension of five weeks. That was a shift of power to the courts. And the prime minister is answerable to the electorate on 12 December only because MPs agreed to this. The power to call an election has shifted to parliament.

While ministers are losing their prerogative powers, the British constitution is becoming increasingly fragmented. Legislation passed at Westminster has decriminalised abortion in Northern Ireland. A former lord chief justice of England and Wales has recommended that Wales should have its own justice system and, in due course, its own chief justice. Scottish and English courts have taken a very different approach to recent constitutional challenges.

It would be wrong to pin all the blame for constitutional imbalance on Brexit – or even on the two prime ministers who have failed, so far, to deliver it. The fault lies with David Cameron for requiring parliament to support a policy that most MPs disagreed with. It was bound to lead to constitutional tensions.

Speaking on my Radio 4 programme Law in Action last week, Professor Alison Young said the British constitution was ‘weak’ because it was based on assumptions that were no longer valid. Governments used to have substantial Commons majorities. Before Brexit, voters used to be divided along party lines. Policymakers were not constrained by external time limits.

In times gone by, one might add, the powers that be used to know how to use the powers they had. Members of the establishment knew how to behave. Downing Street might not have told reporters very much, but its spokesmen did not deliberately mislead them.

How can we resolve these problems? Young, who is professor of public law at Cambridge, suggests making more use of proportional representation – already in use for electing the UK’s devolved assemblies. But countries that have party list systems – such as Israel – may find it difficult to assemble strong coalitions. Should we think about a federal system? Or would that weaken the United Kingdom? A written constitution? But surely that would be too complicated and inflexible.

Young supports citizens’ conventions, groups of people who would meet to consider how the constitution could be reformed. Handled properly, these could help restore public confidence in our institutions. But setting up these working parties and ignoring their conclusions would be more damaging than not setting them up at all.

Perhaps the answer is a further shift in the balance of power. Just as the prime minister no longer has the prerogative powers he once exercised, parliament itself might declare a self-denying ordinance and undertake not to pass legislation in breach of human rights. But how could that be enforced if parliament was sovereign? Only by giving more power to the judges. Young says that courts are criticised by people who have little understanding of how they work. ‘It can be easy to see them as politicised,’ she adds, ‘when they are just taking legal decisions that have political consequences.’

We all can all support improvements to public legal education. But there is little enthusiasm for giving justices of the UK Supreme Court the power their US counterparts have to strike down legislation. After the recent prorogation judgment, commentators such as Charles Moore supported calls for the political vetting of judicial appointments. Those calls have been firmly opposed by the Ministry of Justice, which knows how hard it is to recruit good judges at the moment. But they would be much harder to resist if our Supreme Court had enhanced powers.

Have its justices assumed those already? That was the fear that Lord Neuberger expressed when I interviewed him 10 years ago – before he knew he would be hauled back from the Court of Appeal to become the court’s second president. Neuberger thought there was a ‘real risk’ that moving from the House of Lords to a new building with its own identity would result in the law lords ‘subconsciously perhaps and unintentionally, but nonetheless in fact, arrogating to themselves greater power than they have at the moment’.

I am not sure those fears have been realised. What we need now is a period of calm in which the British constitution can start to rebalance itself. Normally, the courts have no special responsibilities during the run-up to a general election. But I am far from confident that this year’s campaign will simply pass them by.