When I learned Constitutional Law, I was taught that it was an ancient system of conventions, not codified, like European ones. When we dissolved the Empire all the new countries got written constitutions.
The difference, so we were told, was that the British constitution had evolved over a thousand years to be run by 'Gentlemen', who were honourable and trustworthy. They knew the rules of fair play and would always choose naturally to do whatever was the best thing for the nation.
Our lot may be expensively educated, but it seems they are not 'Gentlemen'. So it doesn't work. Do we hope for better in future, or is it time to set about writing a new constitution? (No easy task.)