London | Brexit day – March 29 next year – is just 133 sleeps from now. When just over half of Britons voted to leave the European Union in the summer of 2016, they couldn't have imagined that two and a half years later, with mere months to go, the country and its government would still have no idea what kind of Brexit they are in for.

Brexit is a challenge of seismic, historical significance, an economic and cultural turning point for Britain. Even for a country largely governed by politicians schooled in Oxford University's last-minute essay-crisis mode of making public policy, how could it come to this?