How did it go so wrong?

Now that the UK is in the final phase of leaving the European Union we should ask, before the bell tolls, how much this misadventure - or folie de grandeur - was due to politicians putting their interests above those of the nation, ignoring democratic theory and long-settled constitutional practice.

Democracy, as Abraham Lincoln famously said, is 'government of the people, by the people, and for the people.' He did not, for reasons which should be more obvious, distinguish two versions: the first is 'representative' democracy, where the people elect representatives to enact policies in their name. The second is 'direct' democracy where they vote directly on the policies.

The first says members are elected to serve the interests of the nation, while the second says the duty is to do what a majority wants. The latter goes hand in hand with a movement known as 'populism' which sees itself as a counter to 'elitist' politicians who think they know more about government than a majority, however nominal, transient, ignorant or prejudiced.

The reason for highlighting this distinction is because it is accepted by constitutional scholars across the political spectrum that there is really no room for debate: Westminster democracy has always rested on the former version, with members duty-bound to act on their own judgment after consulting widely and informing themselves as best they can.

Direct democracy was practised in Ancient Greece but exists today only in partial form in Switzerland, where the government (the Federal Council, composed of seven members elected by the Federal Assembly) can hold popular votes - on issues they choose - up to four times a year.

But the idea that a majority should decide all major issues of policy had little appeal after Alcibiades' loss of the fleet at Syracuse, the defeat of Athens and the end of the classical age of Ancient Greece. We should condemn UK politicians, therefore, not for hedging on the promise implicit in the referendum but for making this commitment in the first place. They forgot that democracy means the people elect members but members make the laws.

The clearest expression of this representative or 'trustee' model is found in Edmund Burke's famous address at Bristol in 1774. He spoke to constituents in plain and simple language:

'It is his duty to sacrifice his repose, his pleasures, his satisfactions, to theirs; and above all, ever, and in all cases, to prefer their interest to his own. But his unbiassed opinion, his mature judgment, his enlightened conscience, he ought not to sacrifice to you, to any man, or to any set of men living .... Your representative owes you, not his industry only, but his judgment; and he betrays, instead of serving you, if he sacrifices it to your opinion.'

The Westminster system, in short, sees members as 'trustees' with a duty to represent electors in Burke's demanding sense, whereas the populist model sees them as 'delegates' to do their bidding.

Cameron's action was reckless and presumptuous despite 70 per cent of MPs, for a mix of party-political, economic and national security reasons, as well as on traditional conservative grounds, supporting the status quo. His error was compounded by Theresa May when she deferred her own judgment to a slim majority who were never adequately unformed of grave risks to the economy.

But and this is surely critical, the duty remains to act in the interests of the nation, even if she believed she was honour-bound to keep the promise and found herself weeping in distress at the failure. She did, it seems, act with conviction and courage but this only highlights the difference between an excuse and a justification. Despite her intentions, it was wrong in principle.

Until persuaded by the evidence (not faith and hope) that Brexit is the better choice the duty of trustees is to put the community first, last and always even if, as Burke well understood, it means risking seats at the next election. His idea of duty means government must protect and serve the community come what may.

Parties will often make ambitious promises and later realise that keeping them will undermine more important promises or violate human rights or risk public disorder or end up wasting public money. In such cases they should acknowledge their mistakes and apologize, but still serve the community, however embarrassing and whatever the personal consequences.

It is not difficult to see why Burke was such a great parliamentarian and why his theory of political responsibility was not meant to gladden the hearts of career politicians.