David Cameron in Brussels in 2016. Photo: THIERRY ROGE/Belga/PA Images

If there’s one thing about Brexit that unites both Leavers and Remainers, it’s the view that the exit process is not going smoothly.

One reason for the current travails is that no proper planning for Brexit was done before the referendum. David Cameron called that vote not to give voters a genuine choice, but to shut down a debate that risked pushing him from office. He barred civil servants from preparing for the possibility of a Leave victory. No serious thinking took place about what the process of exiting the European Union would look like or what final outcome might be pursued.

The lesson to learn from this experience is that no politician should ever again call a referendum so nonchalantly. These votes are serious matters. They can profoundly affect the nation—both through their outcomes and through the impassioned debates they often engender. They can enliven democracy and give voters a direct say on an important policy decision. But they can also inhibit reasoned discussion and turn a complex issue into a binary bunfight.

Over the past year, an Independent Commission on Referendums, established by the Constitution Unit at University College London, has been mulling how to do referendums better. Comprising 12 senior people with deep and varied experience of referendums—including impartial experts and politicians from all sides in the biggest recent referendums—the Commission has examined experience in the UK and internationally. Its