Most people think UK courts can strike down laws they dislike. They cannot. But what they can do is far more interesting — and far more powerful than politicians want you to believe.

The mechanism that keeps ministers honest every single day

I believe judicial review is the most underrated tool in British public life. It is not glamorous. It does not make headlines the way a general election does. But it is the reason a Home Secretary cannot simply decide to detain someone indefinitely, or a local council cannot quietly cut your child's special education support without following the law.

Here is the core idea: judicial review is not an appeal on the merits of a decision. As the Courts and Tribunals Judiciary makes clear, the court examines whether a decision was made lawfully, fairly, and within the powers granted by Parliament — not whether the decision was the right one. That distinction is everything.

The process starts before anyone sets foot in a courtroom. Under the Pre-Action Protocol, a claimant must first send a formal letter to the public body, giving it a chance to reconsider. Many disputes end right there. According to Connaught Law, early settlement through pre-action protocols resolves many disputes within two to six weeks without formal proceedings.

The permission filter most people never hear about

If the pre-action letter does not resolve things, the claimant files a claim in the Administrative Court — a specialist court within the King's Bench Division of the High Court, sitting at the Royal Courts of Justice on the Strand and at regional centres in Birmingham, Cardiff, Leeds, and Manchester. A single judge then reviews the papers and decides whether the case is arguable enough to proceed.

This is the permission stage, and it is brutal. Only 26% of applications receive permission to proceed, according to current data. The court is deliberately weeding out weak claims so that public bodies are not paralysed by vexatious litigation.

That filter is actually good design, not a barrier to justice. Critics who say judicial review is too easy to abuse have clearly never tried to get permission. The system is demanding by design.

“Judicial review constitutes an indispensable safeguard against executive dominance within parliament, ensuring that discretionary powers are exercised lawfully and subject to effective oversight.”

— Emma Wills, Law Society of Scotland Journal

What the courts can actually do when a minister oversteps

If permission is granted, the case proceeds to a full hearing. The grounds for challenge fall into four main categories: illegality, procedural unfairness, irrationality, and proportionality. Illegality is the most common — it arises when a public authority simply acts outside the powers Parliament gave it.

When a court finds a decision unlawful, it does not substitute its own judgment. It quashes the decision and sends it back. The public body must then make the decision again — this time lawfully. As the British Institute of Human Rights explains, the authority might even reach the same conclusion, as long as it follows the correct process.

I remember watching the 2019 prorogation case unfold in real time and thinking: this is the system working exactly as it should.

In R (Miller) v The Prime Minister [2019] UKSC 41, the Supreme Court ruled unanimously that Boris Johnson's advice to prorogue Parliament for five weeks was unlawful. The court held that prorogation would be unlawful if it had the effect of "frustrating or preventing, without reasonable justification, the ability of Parliament to carry out its constitutional functions."

The sovereignty question that trips everyone up

Here is where people get confused. Parliamentary sovereignty means courts cannot strike down Acts of Parliament. As the UK Parliament's own website states plainly, Parliament is the supreme legal authority and can create or end any law. No court overrules that.

But judicial review does not challenge Acts of Parliament. It challenges how ministers, councils, regulators, and officials use the powers those Acts give them. That is a completely different thing, and conflating the two is either ignorant or dishonest.

The counterpunch argument goes like this: courts are unelected, so they should stay out of political decisions. I do not buy that. The House of Commons Library notes that the UK's lack of a codified constitution places exceptional reliance on the rule of law and an independent judiciary as safeguards against arbitrary governmental power. Elected majorities can still act unlawfully.

The real cost problem nobody wants to fix

Here is the honest criticism: access to judicial review is genuinely unequal. Court fees increased 3.2% in April 2025, with full hearing fees now reaching £847. Processing times average nine to twelve months for contested cases. Legal aid for judicial review has been cut significantly in recent years.

That is a real problem and it deserves a real fix. A mechanism this important to democratic accountability should not be accessible only to those who can afford a barrister. The Judicial Appointments Commission selects judges on merit and keeps them independent — that part works. The funding side is broken.

Would you trust a system that lets ministers off the hook simply because the person they wronged could not afford a lawyer?

Why this system is worth defending fiercely

Between 2015 and 2024, the Conservative government made repeated attempts to restrict judicial review. According to research published in the American Journal of Comparative Law, only a few narrowly targeted reforms were ultimately enacted — the broader assault on judicial power failed. That is a victory worth naming.

The UK has no written constitution. It has no constitutional court with the power to strike down legislation. What it has is a common law tradition, an independent judiciary, and a process that forces every public body to justify its decisions in open court. That is not a weakness.

That is the architecture of a functioning democracy — and it is more robust than its critics deserve.