Britain is still reeling from the economic and political shock of the EU referendum result. While the nation struggles to get to grips with the consequences of Brexit, many in the UK and around the world are wondering how it came to pass. Certainly, it was a close call; only four percentage points confirmed the win for Leave (51.9%) over Remain (48.1%).

Fortunately, there’s one part of the country which can help us to make sense of the bigger picture: the city of Sheffield. Sheffield’s referendum vote was similar to the national one in a couple of ways. Like the rest of the country, the city voted in favour of Brexit by a paper-thin margin: just 51% voted to Leave, with only 6,000 votes separating the Brexit and Remain camps. And right up until the eve of the result, Sheffield was expected to vote Remain – as was the UK as a whole.

To understand what happened here, we need to go back to April 2014, when UKIP leader Nigel Farage launched his campaign for the European Parliament elections in central Sheffield. For some, this seemed bizarre. Many had seen his party as an electoral threat primarily to the Conservatives. But Sheffield is a long-time Labour stronghold, in a Labour-dominated region. It hardly looked like fertile territory for a party nipping at the Conservatives’ heels. What was Farage up to?

At the launch, he made his intentions clear. Labour’s northern strongholds were very much in UKIP’s sights. Political scientists Rob Ford and Matt Goodwin later revealed that older, working class voters – who had long formed the core of Labour’s support – were becoming disillusioned. They felt “left behind” by social and economic change, and ignored by the political establishment (not least on concerns over rapid immigration from the EU). As a result, many were thinking of shifting to UKIP.

Left behind

South Yorkshire – one of the poorest regions in the UK – was home to many such voters. Although UKIP didn’t win Sheffield in the 2014 European election, its vote jumped by 13 percentage points, and it came a close second to Labour. The party did even better in Barnsley and in Doncaster and Rotherham, where it won.

Two years on, and Farage’s choice of launch location has been well and truly vindicated. UKIP’s core aim was always to take the UK out of the EU. And the recent referendum showed that the majority of Sheffield voters agreed with him.

That said, Brexit was backed by much larger majorities in most of the surrounding local authorities. Nearby Chesterfield, Bassetlaw and North East Derbyshire all voted Leave by more than 60%, while Bolsover’s majority reached almost 71%. Relatively speaking, the city was the most pro-EU place in its region.

Yet Sheffield was the only one of the north’s five largest cities to produce a Brexit majority. The others – narrowly in Leeds and Newcastle, but by larger margins in Manchester and Liverpool – opted to stay in the EU.

The graduate effect

The explanation for Sheffield’s puzzling position lies, once again, with the voters who feel “left behind”. Specifically, it seems as though the Remain campaign won over graduates, but failed to persuade the older, working class parts of the electorate. This is illustrated by the correlation between the proportion of university graduates in the local population, and support for Brexit.

Nationally, this is a very strong indicator. Support for Brexit was much lower among graduates than among other groups in the population, and areas with higher proportions of graduates had a correspondingly lower proportion of Leave voters.

This trend held true in South Yorkshire and North Derbyshire, where the correlation between votes for Leave and the proportion of the population with a university degree is very strong indeed.

Charles Pattie , Author provided

Sheffield is home to the region’s two universities, and over a quarter of the city’s population are graduates. Compared with Doncaster, Barnsley and Rotherham, where only 16% or so of the population hold degrees, it’s not so surprising that support for Brexit was lower in the city than in much of the surrounding area.

A nation divided

The local authorities were the smallest units for which referendum results were released. But it is very likely that the strong correlation above was repeated within the city of Sheffield too. Brexit was almost certainly a less popular option in the south-west of the city (the most middle class area of Sheffield, where a very high proportion of the population holds degrees) than in the more working class east and north.

Indeed, it is almost certain that Sheffield Hallam – the only non-Labour constituency in the region, represented since 2005 by the Liberal Democrats’ Nick Clegg, who was left hanging by a thread in the last general election – will have seen a Remain majority. Almost one third of the constituency’s population were graduates in 2011, so if the region-wide correlation also held within the city, that would translate to 55% voting for Remain. By contrast, the Brexit vote in Sheffield Brightside and Hillsborough – where only 9% of the population hold degrees – would be a massive 81%.

There is anecdotal evidence to this effect. Remain posters predominated in the affluent south-west of the city, while Brexit posters were prominent elsewhere. And support for UKIP in the 2016 local elections was much higher in the north-east of Sheffield than in the south-west.

All of this paints a picture of a city deeply divided; a city where class, education and opportunity have shaped the political understandings of its people. And although we’re still waiting on a demographic breakdown of the results, it’s highly likely that such divisions will have cut through the rest of the UK, too. The case of Sheffield shows that the fracture lines in British society do not just run between north and south, Scotland and England, or rural and urban areas. They run through every community in the country.