A Constitutional MOT for Every Bill: Why 2026 Needs Impact Testing Before Royal Assent

Constitutional reform rarely arrives with a fanfare. It arrives in clause 14, in a Henry VIII power, in a devolution consequential, or in an ouster clause slipped into a bill presented as administrative housekeeping. By the time the courts are asked to make sense of it, the political argument is over and the legal uncertainty has begun. The Government should therefore adopt a simple discipline: every major bill should carry a short, standardised constitutional impact assessment before it leaves the Commons.

The gap in the current machinery

Governments publish impact assessments for finance, equalities, rural proofing and a range of other matters. There is no equivalent for the constitution. That is an odd omission, because constitutional consequences are precisely the kind of consequences that are hardest to correct after Royal Assent. Recent flagship legislation has too often combined broad delegated powers, ambiguous limits on judicial review and devolution consequences that were discovered late in the day. The result is not merely untidy statute law. It is uncertainty for citizens, businesses and public bodies, and it invites litigation that could have been avoided.

A centre-right government should not be relaxed about that. Conservatives believe in clear statute, accountable ministers and Parliament deciding the difficult questions. When a bill leaves gaps, the courts are asked to fill them. Sometimes they do so cautiously; sometimes they do so expansively. Either way, the decision has shifted from the chamber to the courtroom by default. That is not a vindication of parliamentary sovereignty. It is an abdication of it.

Four questions every bill should answer

A Constitutional Impact Statement should be short — no more than four pages — and standardised across departments. It should be published at introduction and updated before report stage. Four headings would do most of the work.

First, rights. Does the bill engage Convention rights or common law constitutional principles? If so, how, and what is the Government's legal view of proportionality and deference? This is not a rival to the existing statement of compatibility under the Human Rights Act. It is a practical summary for members who are not lawyers but who are expected to vote on the issue.

Second, devolution. Does the bill touch on devolved competence, legislative consent conventions or intergovernmental relations? Too often, devolution consequences are treated as a technical afterthought. They are political facts about the structure of the United Kingdom. A short statement would force departments to identify them early and to explain how they will manage them.

Third, delegated powers. Which powers are being taken, why are they necessary, and what parliamentary controls apply? Are there sunset clauses, affirmative procedures or statutory tests? The House of Lords Constitution Committee has done valuable work in this area. A Commons-facing statement would bring the same discipline into the elected chamber.

Fourth, access to justice. Does the bill create ouster clauses, restrict judicial review, alter time limits, impose fees or change tribunal jurisdiction? These are constitutional questions, not mere procedural detail. They determine whether individuals can challenge unlawful decisions and whether courts can perform their proper role.

A workable Commons model

The scrutiny should not be left to the courts after the event. It should be built into the Commons before third reading. The most workable model is a dedicated Constitutional Impact Subcommittee of the Public Administration and Constitutional Affairs Committee, or a new standing committee with a similar remit. It would receive the statement, take written evidence and hold one evidence session with the minister and departmental lawyers. It would then publish a short report before third reading.

The committee should not have a veto. It should have a timetable: no more than ten sitting days from the bill's committee stage, and a duty on the minister to respond in writing to any identified gap. That is enough to concentrate minds without creating a new blocking point. The House would retain the final decision. The purpose is transparency, not technocracy.

This is not a novel constitutional architecture. It uses existing committee staff, existing parliamentary procedure and existing legal expertise. It simply requires the Government to state its constitutional reasoning at the point when Parliament can still act on it.

The centre-right case for clarity

Some on the right will object that this is more bureaucracy. It is not. It is a discipline. The alternative is more litigation, more uncertainty and more power shifting to judges by default. Judicial review is a legitimate check on unlawful executive action. It is not a substitute for legislative drafting. When Parliament legislates ambiguously, it invites judges to make policy choices that elected politicians should have made.

There is also a devolution argument. A statute that ignores the territorial constitution is not merely inefficient; it is a source of grievance. A statement that identifies devolution consequences early would improve relations with the devolved administrations and reduce the risk of last-minute amendments. Business and civil society would benefit from the same clarity.

In 2026, with a crowded legislative agenda and a public impatient for delivery, the case is practical as well as constitutional. Ministers should publish a Constitutional Impact Statement with every major bill. Parliament should scrutinise it before the bill leaves the Commons. That is how a centre-right government demonstrates that it takes both executive power and parliamentary sovereignty seriously.