Brexit will fail whether or not Boris Johnson and Theresa May continue taking jabs at each other

Jobs are at stake. We cannot complete this fractious process without a democratic mandate

When Boris Johnson decides to go on leadership manoeuvres he tends to be noisy. His latest line is that the prime minister is like some sort of incompetent suicide bomber, handing over the ignition button on her suicide vest to none other than Michel Barnier. Presumably, Mr Johnson would like us to believe that he would in fact willingly blow himself to kingdom come, shouting “Leave means Leave” on his way to enjoying the company of the promised 72 virgins of the Leave campaign. These may prove as mythical as the extra £350m a week for the NHS he once promised his own fanatical supporters. Or something like that.

As Mr Johnson has discovered, metaphors around Brexit can easily get misconstrued and extended way too far. With the suicide bomber analogy, Mr Johnson displayed his usual contempt for good taste and, as ever, took delight on winding up his opponents. These include two of his own former ministers at the Foreign Office, Alistair Burt and Sir Alan Duncan, who know his ways well and may be forgiven for letting off steam. Sir Alan called it disgusting. True, but it did the trick: Johnson is dominating the headlines again, just ahead of the Tory conference and crucial EU summits. It’s pretty obvious what he is up to.

On the substance though, there was little new in this intervention. Mr Johnson has, at least privately, let it be known that he regards the issue of the Irish border as a subsidiary one, unnecessarily getting in the way of his vision of Brexit. He apparently now regards the whole question as a plot by closet Remainers to keep the UK either in the EU or as close to the EU as makes no difference – Brexit in name only.

He rejects the notion of the six counties of Northern Ireland becoming part of a special economic area, inside the EU single market and customs union, to avoid the dreaded hard border. Mr Johnson, sincerely or not, regards it as a trivial non-issue. He is wrong. If the UK leaves the single market and customs union then there will need to be some checks at the border, even under a free trade agreement. That is true everywhere in the world where economic blocs meet. The same is true of the channel ports and airports.

The Chequers agreement suggested a “facilitated” customs arrangement as a clever way around it. In theory, it is elegant and admirable: in practice the software hasn’t been invented to cope with it. More than two years after the EU referendum and with huge goodwill everywhere, the best minds across Europe have been wrangling with the Irish border conundrum and failed to find any better answer than May’s. Even the Eurosceptic European Research Group have had to hire a Dutch customs expert to sit in a darkened room with a wet towel around his head until he tells Jacob Rees-Mogg the solution. Certainly Johnson doesn’t have the answer, same as anything else.

The problems of Brexit are not down to a timid PM or gutless cabinet (one in which Mr Johnson continued to serve until this summer). It is inherent in the Brexit project. The EU27 are roughly 10 times the size of the UK. Their exporter needs the UK for markets and profits, yes, but not nearly as much as the British need access to EU markets. We cannot, as the old phrase goes, have our cake and eat it. But, as himself once joked, his policy is to be in favour of having cake and eating it. We have gone beyond such jocularity.

As the latest poll of trade union members makes clear, the public is coming to realise that the country needs to pass its verdict on the reality of Brexit. Jobs are at stake. We cannot complete this fractious process without a democratic mandate. The TUC general secretary, Frances O’Grady, seems ready to help put the Labour movement behind the campaign for a Final Say.

It seems increasingly likely that the sovereign Labour conference will back a popular vote on the final terms of Brexit, with the option of staying in the EU. Mr Corbyn will then be morally and politically obliged to put the people’s demand for democracy first. The Final Say referendum is in play; and now is the moment to push on with the campaign. It is not too late to save the economy.