Britain’s worst politicians, which is to say the leaders of the Conservative and Labour parties, pretend that the democracy of a second referendum is a danger to democracy. Outsiders may believe that the true danger lies in a Brexit that threatens the hard-won peace in Ireland, the union with Scotland, the living standards of the poorest people and regions and Britain’s influence in the world, for the sake of a fantasy that was invented by charlatans and is being implemented by incompetents, so unqualified in statecraft they can neither agree among themselves nor be honest with the public about the dismal choices ahead.

Not so, according to the far left and far right that drive the agendas of the major parties – and when in our history have such minor figures dominated “the major parties”? After all other arguments against putting the Brexit choices to the electorate fail, they turn to the threat of violence. “There will be a backlash the likes of which the political classes in this country simply cannot understand,” warned Nigel Farage. Rather than say that a decent left must fight Farage and the thugs he imagines swarming on to the streets, John McDonnell agrees, as he and Jeremy Corbyn have agreed with Farage on Brexit throughout their careers. Trump’s ally was correct. There cannot be a second referendum because it would provide “opportunities for the far right”.

Once democracies boasted they “would never give in to terrorism”. Now Britain’s leaders say they cannot allow a democratic vote and not only because far-right terrorists could forbid it; Theresa May says a referendum on the Brexit settlement would be “a politicians’ vote” that told the “people they got it wrong the first time and should try again”. Forget if you can the mendacious logic that allows the prime minister to pretend that allowing the electorate rather than parliament to decide is an elite stitch-up and ask yourself: does she or any Tory who hasn’t yet resigned from her administration think that if “the people” learn they have got it wrong, they will blame themselves?

Conservatives were once realists. They knew “the people” never blamed themselves. Now they believe “the people” will greet economic hardship and a long, slow national decline with a stiff upper lip and rousing cheer.

If politicians don’t get the political cover of a second vote, they will be totally exposed Tony Blair

Tony Blair, who I think it is fair to say knows more than most about how the love of “the people” can be given and withdrawn, tells me the naivety of Labour and Tory politicians astonishes him. If they cannot take a stand on political principle, he implies, surely they can stand by the time-honoured cause of self-preservation. As he wrote in the Observer last week, by the 2022 election voters will have learned the falsity of the Brexit campaign’s promises. What ought to be clear now will be blindingly obvious by then: we will either have the powerlessness of following EU rules without a say in EU policy or the chaos of a wrenching break. But that is not all.

Conservative activists, who are growing ever more Faragist, will not thank Tory MPs if they vote for May’s vassal state. Their constituents will not thank them if they ally with the Tory right and push us into chaos. Jo Johnson put it as bluntly as Blair, when he told his brother Boris and all the Leave campaigners that “inflicting such serious economic and political harm on the country will leave an indelible impression of incompetence in the minds of the public”.

Jo Johnson: it would be travesty not to have second Brexit vote Read more

Sane Tory MPs would watch their backs and say words to the effect that they had tried to make the referendum result work. Unfortunately, they had discovered that the options facing Britain are so grim only a second referendum that included the question whether it wouldn’t be better, after all, to stay could decide between them. As Blair puts it: “If politicians don’t get the political cover of a second vote, they will be totally exposed.”

The dilemma facing conformist Labour politicians is as stark. When I interview the cowards among Labour’s northern MPs, they say they must vote for a Brexit they know will hurt their constituents because their angry voters demand it. If you ask whether they believe a Brexit that produces cuts in income and public services will lessen their voters’ rage, the tribunes of the people fall silent, In their hearts, they know it will not and cannot.

The self-preservation principle applies as much on the left as the right. Any ambitious Labour politician must know that a large majority of Labour voters now back Remain. Our coming men and women should also be wondering how much longer Labour members will chant “Love Corbyn, hate Brexit”, a slogan as deluded as “Love cigarettes, hate lung cancer” or “Love beer, hate hangovers”, before they realise the far left has duped them. The next generation of Labour leaders will be Remainers. My advice to unscrupulous Labour hacks determined to get on is to go with the flow or be swept away.

I have almost reached the end without making the essential point, that the right’s concept of the unified “people”, who denounce the “mutineers” and “enemies” who betray them in a single voice, is inherently anti-democratic. It was invented in the terrorist phase of the French Revolution, a sanguinary moment our leaders ought to study with greater care.

As he urged his fellow revolutionaries to dispense with the legal formalities and simply execute Louis XVI, Louis-Antoine de Saint-Just uttered an eternal political truth: “One cannot reign innocently: the insanity of doing so is evident.” British politicians believe that they can play the innocent because the referendum has freed them from responsibility. All they must do is execute the “people’s will” and “the people” will thank them. Saint-Just learned about the people’s gratitude when he went to the guillotine a year after the king. If British politicians do not protect themselves with a second referendum, they will discover in turn that “the people” believe many things about their leaders. But they never think them innocent.

• Nick Cohen is an Observer columnist