BORIS Johnson has this week insisted he is “serious” about taking the UK out of the European Union with no deal, as he bangs his patriotic drum and attempts to draw parallels with the Napoleonic era.

His talk about being “serious” will maybe give some people room for hope that he doth protest too much, and that he is actually only engaging in brinksmanship – trying to take the UK’s extremely weak hand and make the EU believe it is somehow a winning one. Sadly, given the mood among Brexiters, it might be a dangerous assumption to make that Mr Johnson will not take the UK down an unthinkable road to misery.

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While we wait to see how the Tory leadership race between Mr Johnson and Irn-Bru and fish supper photo opportunity man Jeremy Hunt pans out – and what will happen on the no-deal front particularly if the former wins – Boris should focus on the “serious” actualities of Brexit.

He could heed the latest dire warning from the UK car industry, which has already reacted in a big way to the very prospect of the country leaving the EU with decisions to close operations and invest elsewhere. It is an industry that is very heavily dependent on the single market. The Society of Motor Manufacturers and Traders has this week made crystal clear the scale of disruption from a no-deal Brexit.

As Mr Johnson was keeping up a no-deal rhetoric that appears to be appealing to those hard-line Leavers who seemingly want Brexit at any cost, the SMMT declared: “Leaving the EU without a deal would trigger the most seismic shift in trading conditions ever experienced by automotive, with billions of pounds of tariffs threatening to impact consumer choice and affordability.

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“The end to borderless trade could bring crippling disruptions to the industry’s just-in-time operating model. Delays to shipments of parts to production plants are measured in minutes, with every 60 seconds costing £50,000 in gross value added – amounting to some £70 million a day in a worst-case scenario.”

The SMMT warned that, combined with World Trade Organisation tariffs in a no-deal scenario, which it said for trade in passenger cars alone would amount to £4.5 billion a year, a disorderly Brexit would “deliver a knockout blow to the sector’s competitiveness”.

The industry body warned: “We are already seeing the consequences of uncertainty, the fear of no deal.” And it declared: “The next PM’s first job in office must be to secure a deal that maintains frictionless trade.”

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Mr Johnson seems to see the danger of trade tariffs in the event of a no-deal Brexit, yet talks about preparing “confidently” for such an abrupt departure. He declared, in language that seemed unhelpful from a diplomatic perspective, that any attempt by the EU to impose trade tariffs would be akin to a Napoleonic-era blockade. The reference to the Napoleonic wars of the early 19th century will hopefully seem bizarre to many people throughout the UK, even in the context of Mr Johnson’s penchant for dramatic language.

From a Scottish perspective, the seemingly antagonistic and jingoistic attitude of some people in England towards the French is particularly difficult to understand. Then again, the whole Brexit drive and desire is difficult for a big majority of people in Scotland to fathom, as can be seen from the June 2016 EU referendum.

Mr Johnson’s bringing up of Napoleon highlights the yawning gulf between the overall attitude of people in Scotland on the one hand, and those elsewhere in the UK (though not in London and many similarly Remain-minded areas) on the other, to our long-suffering mainland European neighbours.

The University of Strathclyde’s Fraser of Allander Institute this week warned of “serious implications” for the Scottish economy if Brexit makes migration to Scotland more difficult or less attractive. Director Graeme Roy noted a significant amount of the long-term growth gap between Scotland and the rest of the UK could be explained by differences in population growth. On past form, few would expect Mr Johnson to worry about the particular difficulties for Scotland of Brexit. And, while Mr Hunt might like an Irn-Bru and love the Union, it is hard to imagine him arguing for ongoing single-market membership to help Scotland secure the EU workers it needs to prosper.

We have Mr Johnson declaring in his usual gung-ho fashion that he will take the UK out of the EU on October 31 without a deal if it comes to that. A true Hallowe’en horror show. At the same time, he rails against tariffs. Mr Johnson told LBC Radio this week: “I think it would be very bizarre if the EU should decide on their own…if they decided to impose tariffs on goods coming from the UK it would be…a return to Napoleon’s continental system.”

What a state of affairs. We have Mr Johnson engaging in jingoism likely to noise up the EU, telling the bloc’s leaders that the deal they did with outgoing Prime Minister Theresa May is dead and looking for a new one, having been told there will not be one. He then complains – while declaring robustly that he is willing to take the UK out of the EU without a deal – that it would be bad for our neighbours to impose tariffs. Wanting to have your cake and eat it hardly even gets close to describing this incredible approach.

Bank of England Governor Mark Carney, not popular with Brexiters for explaining realities, warned this week that there needed to be “absolute clarity” on what a no-deal Brexit choice would mean for the UK economy, bringing short and long-term damage. He deserves credit for his calm warnings, delivered without fear or favour to politicians, regardless of Brexiters’ baying.

It remains to be seen exactly how the EU will react to the rambunctious approach of Mr Johnson if he becomes prime minister. But the EU has been focused and pragmatic on its dealings with the UK on Brexit so far so it is difficult to see it suddenly pandering to noisy tub-thumping.

And we thankfully have Parliament, which has made it clear it is in no mood for a no-deal departure and rejected Mrs May’s essentially hard EU exit deal, as a brake on, or barrier to, any prime minister intent on visiting a disorderly, recession-inducing Brexit upon the UK.

Hopefully, we might still get to a post-tub-thumping era, one in which the noise of jingoism and Tory infighting dies down and common-sense prevails. And one in which the whole Brexit folly is abandoned, giving a desperately needed boost to a UK economy laid low by the EU exit fiasco and by grim Tory austerity.