Opponents of demagogues from Donald Trump to Nigel Farage have suffered from a huge political disadvantage. They were either politicians who were or had been in power, and had to take responsibility for all the failures and compromises power brings as inevitably as blisters on weary feet. Or they were voters, who thought that mainstream politicians were preferable to the leaders of the far right and left. Demagogues could dismiss them as establishment lackeys, Blairites, liberal elitists, Republicans in name only, and so on. And the dismissals could work. For how many wised-up 21st century voters wants to think him or herself as some establishment drone, some dupe of a failed status quo?

Until the Brexit vote no one could turn round and throw the demagogues’ own record in their faces. They had never been in power. They could claim the purity of the outsider, fighting the elites on behalf of ‘the people’.

After Brexit, their hands are dirty. They will soon be covered in filth because, as everyone ought to know, there is a choice between jobs and restrictions on immigration; between staying in the single market and regaining control of our borders.

Choose immigration controls, and people who voted to leave may end up on the dole. Choose the single market, and all those who thought they were voting ‘out’ to stop immigration will feel betrayed. Whatever choice is made, there ought to be an unrestrained political assault on Farage, Boris Johnson and all the other Vote Leave charlatans. They pretended the British could have control and a booming economy, and should be made to pay a price for their deceits.

The question now is who will deliver the bill, and tell the public that those who shouted loudest about the lies of the establishment turned out to be the biggest liars of all?

Not the Labour opposition, By far the most revealing speech I heard at the Labour party conference came from Rachel Reeves. I do not want to criticise her. She is a decent MP, and I wish that she were leading the Labour Party. Her account of why she would accept a hard Brexit was driven by honourable motives.

Mass immigration had changed her Leeds constituency, she said. She could not go into white council estates to argue for Britain to stay the EU during the referendum campaign. She knew she would not change a single mind. Canvassing would just remind working-class voters to get out and vote ‘leave’ on referendum day.

The nearest she came to seeking working-class support was at a meeting at the largest employer in her constituency, a packing and delivery business. Reeves tried to explain why it was in the workers’ interest to stay in the EU, but was met with unremitting hostility to freedom of movement. Britain has had the largest migration in its history. No one had asked her constituents if they wanted it. Now the referendum campaigners were asking them, and their answer was clear.

Think about Reeves’ position. A Labour MP can canvass support for ‘remain’ among students and the Leeds bourgeoisie, but cannot knock on the front doors of the very class her party was founded to represent. It is an intolerable position. A position that throws the purpose of the Labour party into doubt. And a dangerous position too. For Reeves had had three racial attacks in her constituency since June, and she fears much worse if Westminster fudges freedom of movement.

As a good MP, she has listened to her voters and decided that, if the EU will not allow us to control immigration if we remain in the single market, then we will have to leave the single market. Other prominent Labour moderates think the same, and have said so on and off the record. They had tried to convince their people during the referendum campaign, and failed. They had to accept the result. It sounds a reasonable democratic position until you think about the consequences.

If leaving the single market hurts her packing plant, Rachel Reeves cannot return to give her workers a blunt political education. She and other ‘remain’ politicians will not be able to show how Vote Leave lied to them, and took them for fools, when they convinced a majority of the electorate that Britain would either be no worse off or better off if we left the EU.

Nor will the far left. Jeremy Corbyn did all he could to sabotage the pro-EU campaign because he does not believe in the single market. Outside the EU, the far left dreams it will be possible to build socialism in one country. The Scottish nationalists will doubtless attack, but they cannot speak for England. The Liberal Democrats are too small; George Osborne and Nick Clegg too isolated.

Therein lies the trouble. Mainstream politicians ought to channel the disappointment that will surely soon be upon us. If they don’t, hypocritical demagogues will.

From the day after Brexit, I have argued that far from settling the issue, lancing the boil, or whatever cliché fitted the moment, the Brexit vote, opened enticing possibilities for a new right-wing politics of resentment.

If we accept free movement as part of the deal for staying in the single market, the Tory right, Ukip or Aaron Banks’ planned British version of the Trump movement will be able to roll out all the old tunes. They will say that 'the people' have been 'stabbed in the back' by 'the elite'. Even if we do what so many mainstream politicians now want, and give up the single market in return for border controls, the three million EU migrants in Britain, whose presence disconcerts so many, won’t vanish. To expel them would mean tearing apart marriages and driving thousands of businesses into bankruptcy. We would have to be some ethnic-cleansing Middle Eastern state to even think of trying it, and for all our faults, we are not that. Nor would the need for new migrants to work everywhere from the farms of Lincolnshire to the care homes of Kent vanish. There would still be fresh immigration.

And what about those workers in Leeds? What if they turn out to have been more dependent on the single market than they knew? Rachel Reeves won’t be able to tell them that Farage and Boris Johnson lost them their jobs, because she will now be supporting a hard Brexit. I can hardly see politicians as unscrupulous as these gentlemen admitting they have misled millions of voters. They will try to shuffle off responsibility, and they will get away with it because their political opponents will allow them to get away with it.

In the late 1980s, the European Union became the British right’s 'other': the enemy they defined themselves against. In the 2000s, immigrants joined the EU. So menacing were they, that by 2016 the right could persuade us to vote leave because the EU in its wickedness had allowed unconstrained immigration.

Now we are heading out of the EU, and there is no other 'other' for the populist right to turn on except immigrants. They will be blamed if Brexit brings job losses and falls in living standards. For who else can a right that never blames itself turn on? This isn’t over. It has barely begun.