Grimsby’s once-thriving docks are now almost deserted following the decline of the town’s fishing industry. Photograph: Alamy Stock Photo

“It’s like Brexit isn’t it,” says Tim Rix, a staunch leave supporter and the fifth generation of his family to run JR Rix and Sons. “Donald Trump was voted in for many different – and sometimes conflicting – reasons,” the managing director says. “Many reasons that overturned the establishment’s expected result.”

There are thousands of miles between the rust-belt US states that supported Trump and Rix’s office in Hull in east Yorkshire, but in many respects the two places are closely aligned.

The communities of both quietly voted to shock the world, taking decisions that would reveal deep divisions in each nation and leave large swaths of society asking how this could happen.

Rix sees parallels in the economic protectionism that Trump used to appeal to millions of struggling US middle-class voters. “Europe is broken, it’s not going to work,” he says. “We have our own problems and we need to concentrate on dealing with the problems in this country.”

The mood in those areas that turned against the establishment in the EU referendum is one of economic and social discontent, where people feel left behind and struggle to find their own answers to this and every other question posed by the decline of post-war industrial Britain.

And while Rix and his forebears managed to develop a business that now turns over £4m to £5m, the local area is faring less well.

Following the demise of its fishing, shipping and heavy industries, the city moved into sharp decline. But manufacturing still makes up 17% of the jobs in Hull, compared with 2.6% in London, according to statistics from the Centre for Cities thinktank.

‘A lot of the profit created here does not stay here,’ says Ian Kelly. Photograph: Anna Lehmann

“When the fish industry went down other businesses got more important. We have a lot of global operators in food, chemical, aerospace and oil refineries,” explains Ian Kelly, chief executive of the Hull and Humber chamber of commerce. “A lot of profit that is created here does not stay here. It goes to the business headquarters in London or other parts of the world.”

And so Hull remains one of the poorest cities in Britain, with nearly 30% of households in social housing and one of the lowest average workplace earnings in the UK.

London is perceived as ignoring the region’s problems. “Politicians are not listening,” says Kelly. To illustrate the issue he tells of when, before becoming city of culture in the UK in 2017, Hull applied for £15m to build a bridge to connect its marina to the rest of the city.

“They couldn’t find the money, yet at the same time we read in the London newspapers that the prime minister was signing off £25m for a garden bridge across the Thames – over which there are already several bridges – with hedges and trees on it, and we can’t even get a basic bridge.”

It is the “London bubble” Brexiters so often rail against; a political class concentrated in one place, ignorant or dismissive of problems beyond the city and unwilling to engage with external concerns. Voting for Brexit was intended to prick the bubble.

“You see it with Trump as well. He profits from an anti-establishment feel,” says Kelly.

In Grimsby, 20 miles south of Hull and equally in favour of leaving the EU, Martyn Boyers struggles to see the link between economic hardship and the desire to turn away from an interconnected world.

Boyers, chief executive of the town’s fish market, and whose father and grandfather were fish merchants, says: “There is a lot of people like me in Grimsby. Fishing is part of the community here.” But the decline in the fishing industry has changed the town dramatically, he says. “It was a slow decline that lasted over 50 years. And it started before Britain joined the EU. Coastal areas like Grimsby suffered because of a decline in the deep water fleet. Look at coal mining, look at cotton mills, look at all the big employment – if that goes the area starts to suffer.”

“When I was young, Grimsby was quite a thriving town,” says Margaret Haessig. The 69-year-old retired teacher lives with her Swiss-born husband in a semi-detached house in the town. “We had so many people working, mostly men on the fish docks. Everybody had work.”

When the fish industry went downhill, Grimsby did too. “There was no investment at all,” says her husband, Beat, also a retired teacher.

Martyn Boyers voted to remain in the EU but is optimistic about the future. Photograph: Anna Lehmann

The decline began when the UK and Iceland had a series of confrontations over territory rights in the north Atlantic. The cod wars saw Iceland expand its fishing territory and nowadays 95% of the fish processed through Grimsby’s fish market arrives in lorries from Iceland and Norway.

“Grimsby is not the worst of cities,” explains Mary, a friend of Margaret and Beat. “It’s just a small town where the industry went down.” All three of them voted to remain in the EU referendum, unlike 70% of the voters here. “Because the EU so much improved the ways of our lives,” says Margaret.

But all three of them are as disappointed about the outcome of the referendum as they are the performance of the pro-European politicians. “We have never seen anybody here,” says Margaret. Mary adds: “The politicians have let us down.”

Boyers says: “Nobody – including me – could envisage the consequences of going out. How do they organise fishery, for instance. There are a lot of interests in a small pot.

“A lot of people think that Brexit opens the door to catching more fish. You bring more fish into Grimsby, that will create more jobs, and that creates more prosperity. But it just won’t happen.

“We cannot go back to free fishing. There has to be a form of control for the fisheries.

“You can’t build a fence, like Donald Trump is going to do, in the North Sea. It’s got to be an agreement between Britain and the rest of Europe.”

Wind turbines are bringing investment to the region. Photograph: Henning Bagger/EPA

Although he voted remain, Boyers is optimistic about the future. “This country is resilient enough to come through,” he says. From his office overlooking the port he can see a scattering of wind turbines that have been built in the past seven years.

Dong Energy from Denmark has established windfarms off the east Yorkshire coast and Siemens, the German tech company, invested more than £300m in a facility manufacturing blades and turbines in Hull.

“What you can see from in here,” says Boyers, pointing to three boats in the port, “are supply vessels for the windmill farm. It’s not fish. It’s something completely different, but what this community has provided is the ability to adapt and change.”

Rix in Hull says: “Siemens arriving here was not the end of our problems, but it was the day the economic tide stopped going out.” The whole city had worked hard to attract Siemens. “And what we learned from Siemens coming here was that when we work together a lot can be achieved.”

Shouldn’t this principle also apply to the EU? “Not at all,” says Rix. “In the city we have a common interest. It would be very difficult to build a common interest between all of the nations in the EU.”