Who is really setting the agenda on Brexit? The politician wielding the most leverage has never, in his entire career, held a parliamentary seat, let alone a cabinet position. He runs a party that isn’t a party, with no MPs, no members and no manifesto. But Nigel Farage holds the fate of the government in his hands.

Farage has found himself somewhat overshadowed in recent weeks, as all eyes have been drawn to the new power in Whitehall, Dominic Cummings. But with his threat to stand Brexit party candidates against the Tories unless the government delivers a no-deal Brexit, it is Farage who has blown wide open a long-brewing crisis in the Conservative party. If they don’t give him what he wants, he will hand the next election to Jeremy Corbyn. Most Tories, absurdly, fear Corbyn more than no deal.

Farage intuits the violent longings at work … It was he who augured public violence if immigration was not controlled

The strength of Farage’s position is derived not from what he builds, but from the weaknesses he exploits. As a stockbroker with a nose for vulnerability, he has never led a party capable of taking national power. Whether his vehicle was Ukip or the Brexit party, he has always thrived in elections with low turnouts and which depend more on brand recognition – largely his own brand – rather than on street-by-street campaigning. Its main effect has been to sabotage the Tories. A gambler, buoyed up by hubris, he has taken big risks that no established politician can take. And, as with other radical-right politicians, from Donald Trump to Jair Bolsonaro, detonating a crisis of establishment conservatism has paid huge dividends.

Farage is often called a populist. The main sense in which this is true is that he is not afraid of the dark side of public feeling, whether it is the collective hate of outsiders or the whoosh of excitement as the currency slides, parliament slowly implodes and chaos beckons. To the contrary, he is keenly attuned to the prejudices of middle England, its anguished resentment and its yearning for adventure. He advocates for it and fuses it to his project of creative destruction. It was, after all, Farage and his allies who spotted, well before Cummings and the supposed geniuses of Vote Leave, that people unruffled by European fisheries or subsidy rules would harken to the language of race war. It wasn’t enough just to link the EU to immigration. An atmosphere of national crisis, of “invasion”, of a “breaking point”, had to be invoked, and linked to folk memories of the second world war, Dunkirk and the blitz.

Farage keenly intuits the longings at work in some of the public imagination. It was he who augured, with palpable relish, public violence if immigration was not controlled. It was he who said that if Brexit wasn’t delivered he would don khaki, pick up a rifle and head to the frontlines. The idea of national revival by itself no doubt offers many consolations to people whose life trajectories have been in long-term decline, and who have seen their values rejected by younger generations. But the imagery of war is what makes it compelling. There is a sense in which we all can desire the adventure of violent chaos, but these drives have long been prevalent on the right, where politicians from Margaret Thatcher to Trump have been expert at tapping into them. And, as polling of Tory party activists during the leadership election showed, they are prepared to see a lot that was supposed to be sacrosanct – the Conservative party, the union, even British capitalism – destroyed in the process.

Brexit has become the eschaton of the right, licensing extraordinary measures. In what other circumstance could remain politicians be deemed “quislings”, as Farage dubbed Ed Miliband and Nick Clegg? How else could Tory politicians demand that “extreme” remainers be prosecuted under the Treason Act? In what other situation could an electoral candidate standing for the Brexit party imply that Tory remainers should be dealt with as this country once dealt with “traitors” in the Tower of London? One half of the population is now routinely encouraged to regard the views of the other half as punishably seditious. It can only be the work of a treacherous political class. In such ways has radical-right anti-parliamentarism, not seen on a large scale since 1945, been reborn.

Conservative leaders have tried to conduct these energies into Tory revival, with senior Tories like Sajid Javid larding praise on Farage. Boris Johnson has been better than May at stoking anti-parliamentary sentiment and, with his Churchillian bluster, tapping into war nationalism. He is also ruthless enough to countenance a no-deal Brexit. He has accused colleagues of a “terrible collaboration” with the enemy, as though this were not the country in which Jo Cox MP was murdered by a fascist calling her a traitor. As if journalists so dubbed weren’t being beaten up. As he prorogues parliament to derail opposition, the digital Farageites cheer: finally a politician with “guts”. They can’t lose. There will either be the sort of chaos in which rightwing adventurists thrive or another “betrayal” to agitate against.

Yet the right doesn’t represent “the people”. No deal represents a decided minority. Millions have no truck with end-times nationalism. Even in a deadlocked parliament, it can be defeated. Sadly, Brexit’s opponents have been incapacitated by their fear of popular feeling and by neurotic terror at bringing anything down. Some of them are hamstrung by their equal or greater fear that, if they vote down the government, Corbyn may win an election. Yet, like it or not, his is the only political project with the demonstrated ability to split the leave camp, and countermand disaster nationalism. If they want to stop the radical right in its tracks, the opponents of the Brexit right will have to get over their aversion and take the gamble.

• Richard Seymour’s latest book isThe Twittering Machine