Some elections are landmark events. As in 1918, 1945 or February 1974, they're called not simply because another lustrum has elapsed but because some major issue requires resolution ('What will postwar Britain be like?'; 'Who governs Britain?'). Brexit is obviously the big issue overshadowing this election, but there's far less distance between Theresa May and Jeremy Corbyn on Brexit than between her and Kenneth Clarke or Michael Heseltine, dinosaurs bedded in the Euro-swamp where May herself still languished not a year ago.

The Tories and Labour don’t disagree on leaving the EU. Either could campaign on the slogan: oldthinkers unbellyfeel Brexit. Last year's referendum 'debate' awakened the thoughts that neutrals are likely to have when there's a cup-tie between, say, Chelsea and Manchester United: how unfortunate that one of these sides has to win. On the strength of the dismal campaign, nil-nil would have flattered both. Remain had no thoughts worth registering about how the dysfunctional Euro-behemoth might be restructured, and Leave was no less vacant about how Brexitland would work after quitting the EU. Now the vacuity of the referendum threatens to transplant itself into the general election campaign.

May, a leader whose 'strength' runs to an ability to spin on a sixpence – over Brexit; over last month’s budget; on having an election this year – appears to be in for a landslide. A Sunday Mirror poll had the Tories on 50 per cent. Apart from grabbing the chance to trounce Labour by calling an election now, May presumably reckoned that if she waited till 2020 the Tories might be spattered by the turd-to-turbine prang of the Brexit deal.

If this was her worry, it's probably overdone: in the short term, at least, any such deal, no matter how crap, can always be branded as spoilsport Eurocrats stopping us proud Brits from chucking our rattle out of the pram – indeed, for these purposes, the crapper the better. Cue red-top fury when Britain can't get full single-market access while stopping free labour movement from the continent; when it can't claw back its post-referendum EU budget contributions, or gets surcharged for leaving; when Brussels expects treatment for EU citizens in the UK similar to Britain's demands for its expats in Europe; when the terms seem to jeopardise security co-operation, interoperable healthcare, and so on.

For his part, Corbyn made warm noises to Andrew Marr on Sunday about Britain's not becoming a North Sea version of the Cayman Islands. Labour's manifesto won't come out till next month, but Corbyn doesn't seem minded to hold out for free movement, as opposed to guarantees for non-British EU citizens already in the UK. Labour has some sensible policies on reversing the free school fiasco, inequality, low pay and mitigating sado-austerity, though there's little chance that the manifesto will pledge to cancel the white elephant of Trident's replacement. But the policies will struggle to get much of a hearing over noise about the leader.

Since May called the election, the idea has been floated of a 'Progressive Alliance' that might even extend to standing left-unity candidates in seats where splitting the non-Tory vote will let the Conservative candidate in. This idea was a non-starter even before Tony Blair gave it his kiss of death at the weekend. Since, in England, the non-Tory vote mainly comprises Labour and arch-Remainer Liberal Democrat supporters, something coherent about Brexit would have to be said to attract both lots of voters, and it's far from clear what this might be.

It's said that the support of the 48 per cent of the country who voted to stay in the EU is there for the taking by parties like the Lib Dems who backed Remain. This is folk psephology. YouGov polling suggests that more than half of the 48 per cent now think that Britain should get on with Brexit. This, besides heartfelt apathy about the EU, may explain Corbyn's stance. The trouble for him and Labour is that the public will think, now the satnav's been set for Beachy Head, there's nothing to be gained by changing the driver.