Until recently, we used to comfort ourselves with the thought that the United Kingdom’s uncodified constitution was a great national strength. We didn’t need guidance laid down in one document because precedence, compromise and common sense were enough to ensure the smooth operation of power. As soon as a document is written, power passes from democratic institutions to courts where activist judges can interpret these documents in a political way. In Britain, this is not meant to happen. Our legal system has been seen, world over, as politically neutral, one of the most trustworthy in the world.

So what are we to make of a Supreme Court granting itself powers over the government? The courts used to refuse to adjudicate political squabbles, so why have they started now? There are two answers. One is the rise of a new breed of activist judges, who aspire to an American-style system where politicians make judicial appointments in an overtly political system. The other is two decades of constitutional reforms, which have steadily weakened the system.

The current paralysis of government can be traced back to David Cameron and Nick Clegg’s Fixed-Term Parliaments Act — a stitch-up to ensure that a Conservative prime minister could not pull the plug on his Liberal Democrat coalition partners and call an election when the polls looked favourable for the Tories. If only both parties had felt able to trust each other more on this point. Instead, they created legislation which has had the unforeseen consequence of allowing opposition parties to hold a Prime Minister hostage who does not have a majority.

The impasse over Brexit demands a general election. The current parliament has shown repeatedly that it cannot agree on a solution to Brexit. It cannot approve a deal; nor can it approve no deal. It has no confidence in Boris Johnson, but it won’t allow him to step down and call an election. There are about 40 MPs who no longer represent the party they were sent by voters to represent, and are in no rush to meet these voters again. We are in stalemate, with parliament unable to do anything other than to keep on prolonging our membership of the EU in short instalments. This impasse was impossible in the British system, until Cameron’s Act.

It was also impossible for parliament to become a place where opposition MPs can govern. They do so because John Bercow, who was elected speaker as a practical joke by Labour MPs in order to wind up the Tories, changed the rules. An anomaly of the new British system is that the Speaker can behave like a tyrant: he is the one part of the constitution the Court will not step in to stop, a point confirmed by the Supreme Court. So actions by the Prime Minister in parliament are justiciable (according to powers the court this week granted itself), while the Speaker is a law unto himself. This creates the potential for much mischief.

The decay has been years in the making. Rare is the big political decision which does not now end with a judicial review or some other legal challenge. Well-funded activists have realised that if their lobbying of parliament fails, they have a second opportunity to express their case — through guerrilla action in the courts. It might not always succeed, but it is fine publicity and an act of harassment in and of itself, which may dissuade ministers from taking on the activists in future. As for ordinary people, they have no voice at all.

Meanwhile, the Speaker interprets the rules as he sees them. Parliament’s members break campaign promises, manifesto commitments and even slide around from party to party. They can be immune to criticism, because they won’t permit an election. Parliament is supposed to be a place where MPs go to represent voters. Today, it has become a place where politicians hide from them.

Since the Victorian era, our constitution has had four pillars: the government, the lawmakers, the judges and — less recognised — the press. The success of our constitution has always depended on the balance of powers between them. The prime minister and government ministers are also law-makers. The Lord Chancellor, our highest judge, was also a member of the government: the law lords were parliamentarians, too. As for the press, it had a privileged role in being allowed access to ministers, parliament and the courts.

Tony Blair began the destabilisation of our constitution by replacing the law lords with an EU-style Supreme Court, which, as demonstrated this week, fancies itself as a rival to the government and parliament. The press has narrowly escaped regulation by parliament but the threat still hangs over it. Judges, meanwhile, increasingly feel free to make laws rather than simply interpret and enforce them. Blair’s Human Rights Act has greatly exacerbated this process by incorporating vague principles into law, open to a wide range of interpretations, which have empowered the courts. Through it all, government has been successively stripped of its powers to the point where it can now do nothing.

The issue of Brexit may or may not be resolved on 31 October. But whether or not we leave by that date, it is certain that an even greater issue — the balance of power in our constitution — will not be resolved by then. The emerging battle between the pillars of our constitution is one that the next government will have to resolve.