Japan's car makers won't be alone in quitting Britain if we fail to heed their warnings

The latest rosy economic data won't matter in the long term if we don't treat our friends and allies better and listen to what they have to say

A member of Nissan's manufacturing staff works in the body shop at their plant in Sunderland (Getty)

Oh dear. The latest Markit CIPS numbers on services are out, and they provide further evidence of a post-Brexit bounce back following last week’s manufacturing release.

Why the “oh dear”, I hear you ask? Well, it comes shortly after the Japanese issued an unprecedented 15-page warning to the UK at the G20.

This country gets about half of Japan’s investment in the EU. Companies including Honda, Nissan, and Mitsubishi all make their homes here, as do many other big Japanese businesses.

“Japanese businesses with their European headquarters in the UK may decide to transfer their head-office function to continental Europe if EU laws cease to be applicable in the UK after its withdrawal,” the report warned. Ouch.

And then along came those numbers, proving fodder for the false argument of Brexit backers that it’s all going to be ok after all and all those dire warnings about the consequence of quitting the EU were just so much tosh put about by Remainers like me. Japanese misgivings? Pfah, we’re alright Jack!

It doesn’t matter how many times you repeat it, people still wilfully ignore that the impact of Brexit will only truly be felt over the long term. If there is a Brexit, and guess what, it seems all those plans for a points-based immigration system have been binned.

That might provide some cheer to corporates, which have been wondering from where they’re going to get the people they need in future (ditto the NHS for that matter). But there’s no reason to celebrate.

That Japanese warning should be headed. Just as its car companies employ thousands of people in skilled roles that pay decent money in places where that isn’t easy to find.

It isn’t just the car plants. They all have supply chains, employing still more people. Those employees' spending power sustains still more jobs.

Imagine if those car plants suddenly closed their doors. If their owners decided in a fit of pique that they were walking out of the door. Like the UK, in a fit of pique, decided it would walk out the door of the European Union.

It probably won’t happen like that. More likely is a steady decline in their size and the number of people they employ. The City of London faces a similar situation.

Unless, that is, the UK remains in the single market.

And yet, the reaction of some commentators in response to Japan's report was almost surreal. One opined that Japan’s economy is faltering and that it needs us. Others pooh poohed its concerns. Another suggested it might be no more than a veiled warning not to cosy up to China, as the UK has been doing.

All that madness along with the default response of the Brexiteers when anyone from overseas ventures to suggest that leaving the EU might not be such a good idea, and that there will be damaging consequences: deny, deny deny. Or to throw the toys out of the cot and indulge in a tantrum. We’re the British Empire don’t you know! They need us.

No. They don’t. And we’re not an empire. The creation of the one we did have was a criminal undertaking, unless you think waltzing into other people’s countries and taking them over is a good idea. These days we tend to wag our fingers when other countries indulge in that sort of behaviour.

In the EU we’re a mid ranking power, with an ok economy, that needs to cultivate good relations with our trading partners to ensure it stays that way.

Outside of it we’re in a mess, and we desperately need our trading partners to play nice, even if they don’t have much reason to do so. They’ll have even less if we ignore their concerns in favour of being rude about and to them. It won’t just be Japanese that will say sayonara either.

When our friends speak to us we should listen, just as we expect them to listen to us when we raise concerns with them. That’s how grown-up, sensible people conduct business. Sadly, it seems, there aren’t many of them in the commentariat. Worryingly, it seems that there aren’t many of them in Westminster either.