Brexit's Constitutional Impact
How the Brexit process exposed and reshaped fundamental assumptions about parliamentary sovereignty, devolution, and the UK constitution.
The Sovereignty Question
Brexit was sold as a restoration of parliamentary sovereignty: 'Take Back Control' was the Leave campaign's slogan. Yet the Brexit process raised more questions about sovereignty than it answered. The 2016 referendum was advisory, not legally binding, yet Parliament felt politically unable to ignore it. The result was a collision between popular sovereignty (the referendum result) and parliamentary sovereignty (Parliament's right to make law), two principles that had never previously been in open conflict.
The Miller case (2017) established that the government could not trigger Article 50 to leave the EU using royal prerogative alone. The Supreme Court ruled that only Parliament could authorize such a fundamental change in constitutional arrangements. This reasserted parliamentary sovereignty in law, even as Parliament was effectively compelled by political reality to implement the referendum result.