Boris Johnson’s departure from British politics leaves an expensive legacy.

His period as Tory leader and prime minister may have been ended because of lockdown breaches but the greater offence has gone unpunished, his contribution to the fateful Brexit referendum campaign in 2016.

He was the central character in the Leave campaign and went on to champion an unnecessarily damaging implementation of the electorate’s narrow verdict. The biggest decision the UK has faced in recent decades was trivialised by Johnson in chaotic fashion well before the referendum campaign even started.

Most European democracies over the last few decades, especially since the financial crash of 2008, have seen the disaffection of voters from mainstream political parties and the rise of populism, mainly on the right but sometimes on the left.

In the UK, this took an unusual form: the conversion of the formerly mainstream Conservative party to the agenda of its challenger on the far right, the UK Independence Party of Nigel Farage, essentially an English nationalist party with no support in Scotland, Wales or Northern Ireland.

In countries with proportional representation, Farage’s UKIP would have won a slice of seats in parliament for itself and Boris Johnson might never have ascended to deliver the ‘hard’ Brexit with which his successors will wrestle for the foreseeable future.

Populism thrives on the belief that complex problems have simple solutions, and ‘Get Brexit Done’ was his fatuous remedy to the political paralysis which followed the 2016 referendum.

This had been posed as a binary choice between Remain and Leave, just tick the box, details to follow. The referendum was promised by David Cameron to staunch vote leakage to Farage in the expectation that actually departing the EU would not be the outcome.

He had to deliver on the promise, expected Remain to win, lost narrowly and quit the following morning

His 2013 commitment to an in-out referendum was conditional on an overall Tory majority at the 2015 general election which he did not expect to happen. He had to deliver on the promise, expected Remain to win, lost narrowly and quit the following morning.

Campaign

During the campaign, it was quite clear what ticking the Remain box would mean but Leave could mean anything from extra health spending to instant worldwide free trade and Britannia Unbound. Cameron forbade the Whitehall officials from preparing a strategy to pursue in the event of a Leave victory or even a factual explanation of what it would mean for the UK to depart the single market and the customs union.

The perception that the banking bust was the handiwork of a careless and self-serving elite paved the way for the populist right in many countries and for the populist left in a few. Parties of the populist right hold power in Italy, Hungary and Poland, are part of governing coalitions in Latvia and Sweden and have substantial support in Finland, the Netherlands, France and several other EU countries.

The economic damage is finally becoming clear to voters

Left-populists have held power in Greece and came close in Spain. But nowhere has the fallout been more damaging than in the UK, where no right-populist party actually prospered but the Farage ideology instead captured the Tories, the traditional party of government.

Many of the leading Brexiteers had been long-term campaigners for departing the EU, but not Johnson. While he was undermining his predecessor Theresa May early in 2017 as she sought to fashion a workable form of exit, it was revealed that he had written two alternative opinion pieces for the Daily Telegraph before the referendum, one endorsing Leave, the other Remain.

He chose the Leave piece for publication and that decision propelled him to a leading role in the Leave campaign, when 51.9% of voters were persuaded. It is not known if he actually tossed for it.

The UK does not have a written constitution and referendums are never mandatory. The government of the day can choose to put an issue to the public as a kind of monster opinion poll and has done so very infrequently.

Political expediency

The 2016 vote was only the third national plebiscite and all three were held for reasons of political expediency. In 1975, the Labour government fought and won a referendum on membership of the EEC as it was then known.

The Tory government had secured British admission in 1973, lost the 1974 election, the incoming Labour government was split and opted for the UK’s first ever national referendum to appease the party’s-house Eurosceptics.

David Cameron followed the same playbook in 2016. In between, there had been a referendum on proportional representation in 2013 to satisfy Cameron’s Liberal Democrat partners, easily defeated by the Tory/Labour duopoly.

The economic damage is finally becoming clear to voters, opinion polls show a majority feel Brexit was a mistake and there are calls for a written constitution.

When the history books are written they will not be kind to Boris Johnson.