Brexit has made Northern Ireland’s politics even more complicated, with some believing a Conservative majority could lead to a united Ireland

James Matthews has heard that Boris Johnson is a backstabbing traitor who will sell Northern Ireland loyalists down the river. The loyalist sighs. He still wants the prime minister to win the election. “It’s all mixed up at the moment.”

When the contradictions become too much and his head throbs from the paradoxes, Matthews, 76, a retired painter from Holywood, Co Down, retreats into meditative silence. “I turn off the radio.”

He is not alone. This Brexit election has swivelled the usual political signposts for unionists, nationalists and non-aligned voters. Remainers have reason to back Brexiters, nationalists have reason to cheer Tories, and unionists have reason to hope Jeremy Corbyn, a Sinn Féin sympathiser, ends up in Downing Street.

Northern Ireland has passed through the looking glass into a campaign where voters are asked to believe as many as six impossible things before breakfast.

The election is a combustible cocktail that combines questions about the region’s constitutional status with economic uncertainty, tribal allegiance, tactical voting, profound weariness and widespread confusion. “I consider myself a socialist but I’d probably want Boris Johnson to win,” said Billy, a 56-year-old Belfast punk rocker. “I never thought I’d say that. But that’s the effect of being here, that’s Northern Ireland.”

Voters in England face dilemmas in choosing between Labour, the Tories, the Liberal Democrats and Brexit party, but they are spared counter-intuitive imponderables that confront Northern Ireland voters.

Sinn Féin opposes Brexit but it is holding a conference in Derry this weekend amid the giddy prospect of a victorious Tory PM ramming through a deal that advances republican goals. “What Johnson proposes in terms of an all-Ireland economy arguably advances the cause of Irish unity more effectively than the abstention, armed struggle and episodic participation which have characterised republican tactics over the years,” Jon Tonge, a political analyst, wrote in the Belfast Telegraph. “All-Ireland regulation of goods? Tick. An All-Ireland customs regime, even if Northern Ireland formally remains with the UK’s? Tick. Goods travelling between Great Britain and Northern Ireland treated as exports not internal trade, if likely to head onwards to the EU? Tick. Unionists apoplectic about what they see as the marginalisation of Northern Ireland within the UK? Tick.”

Nationalist parties have agreed an electoral pact under a pro-Remain banner that will prove hard for some people to swallow. By standing aside in Belfast North to boost Sinn Féin’s chances – and obtain a quid pro quo in Belfast South – the SDLP is asking supporters to set aside their scorn for Sinn Féin and its policy of abstention.

Unionist Brexiters face even sharper quandaries. Do they accept Johnson’s assurances – and those of some business leaders – that the deal would be an economic boon and barely tinker with the union? If so do they vote against the Democratic Unionist Party (DUP), which wants to kill the deal, and with it perhaps Brexit’s last hope? George Chittick, 76, a retired civil servant, is torn. “It’s about getting out of Europe. It’s a corrupt regime.” A deal that weakens the union would be a steep price, said Chittick. “If Boris Johnson does the dirty on us we’ll do the dirty on him.”

But Chittick worries more about Corbyn winning power. “It has to be the Tories. If that means Boris’s deal, so be it.”

A hung parliament could restore DUP leverage at Westminster while presenting an acute predicament.

Try to patch relations with Johnson, who threw the DUP under the bus, in hope of negotiating a new deal? The resulting imbroglio could torpedo Brexit – which gives Remainers reason to roll the dice with the DUP. Or it could lead to a no-deal crash-out that wreaks havoc on Northern Ireland. Or should the DUP support a Labour leader branded by many unionists as an IRA fellow traveller?

Logic points to Corbyn, Newton Emerson, a unionist commentator, wrote in the Irish Times. “Labour … is promising to negotiate a soft Brexit withdrawal agreement that would solve the DUP’s sea-border problem, followed by a second EU referendum that could solve all the DUP’s Brexit problems.”

The party’s first election broadcast in Northern Ireland, aired last week, resolved the contradictions by making not a single reference to Brexit.