The car industry is in the early stages of a massive shakeout and the evidence is that Britain will be one of the biggest losers. Ford’s closure of its Bridgend engine plant from September next year, which the US firm announced last week, is just the latest instance of the UK’s largely foreign-owned car industry shutting up shop.

Honda announced in February that it planned to shut its Swindon plant in 2021 with the loss of 3,500 jobs. In the same month, Nissan reversed its decision to build the new X-Trail vehicle at its Sunderland plant.

More recently, Jaguar Land Rover, which is Britain’s largest carmaking operation, said it would be cutting thousands of jobs after its Indian owner, Tata Motors, revealed its UK arm suffered a £3.6bn loss over he previous year.

How much of this decline can be laid at the door of Brexit is a subject of heated discussion. There are few clues from the recent public statements of the car companies themselves. Keen to avoid upsetting Leave voters, most of them have refused to cite Brexit as a reason for plant closures. Behind the scenes, though, executives talk about little else, ranking Brexit among the top two or three reasons to curtail investment in the UK and switch production to sites inside the European Union’s single market and customs union.

To say car company bosses are shellshocked by recent events is to vastly understate the impact of the referendum vote, coming as it did in the aftermath of the diesel emissions scandal and amid pressure to develop a new generation of electric vehicles.

The government’s chaotic response to the vote tells the car industry that its commitment to an industrial strategy, much like its talk of a “northern powerhouse”, is skin deep.

Senior executives in the steel industry, the plastics industry, aerospace and the chemical industries, all of which are under severe pressure, like their car company counterparts, to invest huge amounts in cleaner production methods, say much the same. Why invest in the UK when imports and exports could be the subject of extra tariffs, extra paperwork and delays at the border? These are businesses that not only employ large numbers of people on good wages, they also generate much of the UK’s exports, helping the balance of payments.

Making matters worse, a large slug of heavy industry is tied to the car industry, meaning that further vehicle plant closures will have a domino effect felt most acutely, though not exclusively, in regions where the manufacturing sector is still a major employer, namely, the north-west, the Midlands and Wales. To lose these businesses would be for the long, steady decline of Britain’s industrial base to be put on the equivalent of a perilously steep helter-skelter ride to oblivion.

Only four years ago, the future looked very different. Annual car sales in the UK were surging to a record high of 2.63m. Car production was heading back to levels not seen for decades and investment in research and development was on the up.

Ministers would refer to the sector as the jewel in the UK’s industrial crown and the former chancellor George Osborne could regularly be found in a hi-vis jacket and hard hat touring a car factory or sitting on a fork lift truck, shouting about the “march of the makers”.

And he was right to do so. Sensible governments expect a vibrant economy to operate by one of the many 80:20 rules that govern economic life. That is to say, developed economies begin to live beyond their means when the level of activity in productive industries falls below 20%. Without employment in well-paid, steady jobs making things, a nation’s services sector is built on sand.

Many of the economists who promoted Brexit argued that the UK’s manufacturing industries and agriculture could be allowed to wither and the 32 million-strong workforce could devote themselves almost exclusively to providing services.

It’s a fallacy that even the Swiss, better known for their chocolate and cheese, have refused to swallow. Like the UK, Switzerland has an overly large finance sector, but has kept its manufacturing base, which accounts for more than 20% of economic activity. The same can be said of every other European nation, which relentlessly woo manufacturers to base factories inside their borders.

An industrial strategy, promoted by the business minister, Greg Clark, was supposed to support the car industry’s transition from the combustion engine to battery-powered cars. The government has poured tens of millions of pounds into subsidies for battery research and, over time, that should help retain some of the industry in the UK.

But as the car industry’s successful years show clearly, all the cogs that go to make a new car need to mesh together and that includes the political sphere.

Brexit means that the politics are almost entirely negative. Ministers are distracted and decisions are delayed while the threat of the worst possible outcome – a no-deal Brexit – still remains a possible outcome.

It would be a disaster if Britain emerges from its Brexit wrangling to find that a car industry painstakingly rebuilt from the ashes of the 1970s has quietly slipped over the Channel.