Remainers are poised to fend off no deal, but what will they do if Boris Johnson secures one?

What if there is a Brexit deal? What if, despite the initial mood music to the contrary from the EU and the Johnson government, they came to an agreement? Perhaps not at the 17-18 October summit but at a later date? The story of whether a deal is possible ebbs and flows wildly.

And because the Brexit process is being conducted like a daily soap opera, the broad outlines of the plot are in danger of being lost sight of. Bloodcurdling warnings of the consequences of a no-deal Brexit, or threats by Dominic Cummings, have rather obscured the prosaic reality that “no deal” is still unlikely to happen and that most of us are conducting our lives on the assumption that it won’t. The fact remains that for now “no deal” would be unlawful unless the Commons consents, and it won’t.

The prospect of another three-month postponement and the reassurance of the legislation precluding a no-deal Brexit have no doubt contributed to the current mood. But isn’t an agreement altogether more likely?

It is genuinely difficult to judge whether the UK government is sincere or is preparing the ground for a “no deal” versus Remain election: the people versus parliament; plucky little Britain versus the Goliath of Ireland, backed by its thuggish EU friends.

There are members of the cabinet, many Tory MPs and, apparently, 40 Labour MPs who think, by contrast, that the Johnson “deal” is serious and negotiable. They may be deluding themselves but we can’t just assume that they are.

If the Johnson proposals do germinate into an agreement it is clear how this would happen. It will require the Johnson government to beat a retreat while saving face through defiant rhetoric, and for the EU to remove the swear word “backstop” from their vocabulary, including in the withdrawal agreement. The UK government has already conceded that the whole of the island of Ireland should remain part of the EU single market. The requirement to obtain the consent of Stormont has been announced without great conviction; the capacity of the DUP to insist on consent has been greatly weakened as the loss of a government majority in parliament which means that their votes are no longer crucial, and the assembly no longer sits in any event. It won’t take much to move from “consent” to “consult”.

The second and crucial step would be to make a firmer promise by the UK to honour EU environmental, labour and consumer standards. The Brexiteer fundamentalists will fume but no one will resign in principle over taking back control to reduce standards; Johnson himself almost certainly doesn’t care a fig; the Europeans do care and so do Labour MPs. The withdrawal agreement already binds the UK to four years under state aid rules. Don’t be surprised to see other “level playing field” standards added.

That leaves the proposed customs checks and the Irish border for customs. The argument is becoming theological: when is a check virtual or real? What is a border when it isn’t at the border? Yet theology has divided Ireland for centuries and we should not underestimate its potency. An obvious move, however, is for the UK to agree that there are temporary, not permanent, customs checking facilities on the borders of Great Britain, not across Ireland, which could be replaced when the promised foolproof technology has evolved to eliminate physical checks (it may never… but this is all about symbolism, not substance).

It may be that I am overestimating the ability of the famously flexible Boris Johnson to twist and turn. Perhaps he really is trapped by the Brexit Party and its avatar in Downing Street, Dominic Cummings. We are told that an election is imminent (not for the first time). But it may well produce an outcome not greatly different from now (if my party won, of course, Brexit would be over the next day but that is not, sadly, the most likely outcome).

My serious worry is that the Remain artillery is currently facing in the wrong direction. It is well placed to shoot down a “no deal” option but not for a battle with a slightly modified Johnson deal. The horrors of “no deal” are talked up so much (both by the government and the Labour Party) that some Remainers, or neutrals, will now sign up to anything called a deal. The slogan “Get Brexit Done”, however dishonest and wrongheaded, has resonance.

We must not lose sight of the fact that the deal negotiated by Theresa May, now restyled, is a thoroughly bad one. It offers no certainty or clarity to individuals or business since we shall spend the next few years negotiating a new arrangement of vast complexity with our European neighbours. The two ingredients which once offered the possibility of a “soft”, economically harmless Brexit have (almost) gone: membership of the single market and customs union. The so called “opportunities” mainly now boil down to an agreement on damaging terms with Donald Trump’s administration, whose long term prospects for delivering a major trade agreement now look poor. The Brexit issue won’t “get done”; we’ll merely pass through one door in the labyrinth.

If some sort of deal is reheated at the eleventh hour, a referendum remains an absolute necessity. Cross-party efforts through Best for Britain and others must now redouble to find a majority for a confirmatory Final Say referendum. It would be a democratic scandal for a pig in the poke rehash of the May agreement to squeak through parliament with a tiny majority and no mandate from the public.

The Johnson proposals offer neither control for our parliament nor prosperity for our economy, just years of more uncertainty. The task for those of us who hold hopes of remaining in the EU is to win that argument. Public opinion has moved in our direction. But the forces of Remain are currently unprepared and disunited. For the coming referendum or election, we have to get battle-ready.

Sir Vince Cable MP was leader of the Liberal Democrats 2017-2019 and is a former secretary of state for business