“I’ve voted Labour all my life. My dad would say, ‘if you vote Conservative, don’t think about coming back home!’” Pauline Shanton chuckles, over an afternoon half with two friends in The Albion. “You weren’t allowed to vote for anything different from your family,” one nods. “It was always Labour.”

Jazzy muzak and the burble of fruit machines float through the spacious pub on the corner of Old Hall Street in Hanley, one of six towns that make up Stoke-on-Trent. Pauline, 68, who has lived in the Staffordshire city all her life, will be voting for a new MP on 23 February.

A by-election was triggered in the Stoke-on-Trent Central constituency – which has been Labour since its creation in 1950 – by the MP Tristram Hunt standing down in mid-January to run the Victoria & Albert Museum in London. “He’s a posh git, isn’t he?” Pauline grins.

She will be breaking her life-long Labour allegiance and voting for Ukip’s candidate and party leader, Paul Nuttall. “Because of bloody immigration,” she tells me. “I don’t want to sound racist, but people are coming into this country and nobody else has the guts to say that this is the reason the NHS is in a state.”

Now retired, Pauline worked in the Doulton pottery factory for most of her life. Stoke’s towns are known as the Potteries, as historically they were at the heart of the ceramic industry. The Doulton factory closed in 2002. Most of the other big pottery factories also closed or shrank, reducing a 70,000-worker strong industry to the mere thousands. “You could leave one factory, and find another job the next day,” recalls Pauline. “Now the [coal] pits are closed, the steelworks have gone, along with the pottery. That’s the bloody Conservatives for you.”

Pottery and industrial pride may be central to Stoke’s history, but the city’s modern identity hangs in the balance. Memories of Tory government attacks on manufacturing make the Conservatives unpopular among the chiefly urban, white working-class population.

But Labour isn’t faring so well either. It has shed 14,000 parliamentary votes since 1997. Hunt was elected by merely 19 per cent of constituents, in a seat with the lowest turnout (49.9 per cent) in the 2015 general election. And its leader doesn’t help matters. “I wouldn’t vote Labour now,” Pauline shakes her head. “That Jeremy Corbyn is an arsehole. He wants to let them all in. If he got in, he would let them all in!”

Ukip is relying on voters like Pauline to beat Labour here. It came second in the general election, with 22.7 per cent of the vote – 5,179 votes behind Labour. Its calculation is that if it can turn out more voters, of the sort who loathe the Tories but feel overlooked by Labour, then it can have its first original Ukip member elected to Parliament.

“We just need to get out our vote, that’s the key,” Nuttall tells me, when I drop in to his campaign HQ in Hanley. He is in full Ukipper day gear: tweed jacket, tweed flat cap, blue jeans, brown brogues. His ginger-flecked beard and green eyes are magnified on a banner plastered across the shop front. “We know that there are a huge amount of people who voted Leave,” he says. “If we can convert people who voted Leave into voting Ukip, we’ll go on and we’ll take this.”

Stoke has been dubbed UK’s “Brexit capital”; 69 per cent of voters in Stoke-on-Trent voted Leave. Ukip’s bet (Nigel Farage has £1,000 riding on it) is that focusing on the referendum could drum up the votes Nuttall needs to reach the Commons.

This view of the by-election doesn’t benefit Labour’s candidate Gareth Snell. The local councillor was outed as a rather aggressive Remainer via a number of embarrassing tweets he sent at the time, one of which called Brexit “a pile of shit”.

But Ruth Smeeth, Labour MP for Stoke-on-Trent North and the powerhouse behind the campaign, tells me it’s “nonsense” to see this by-election as a referendum rerun. “All the other political parties are trying to rehash the debate that we had last year for the referendum,” she tells me. “We’re the only party in this by-election that is focused on making Brexit work for the community. Everyone else is talking about whether we should be leaving or not.”

All parties agree that Stoke has been overlooked by successive governments. Shuttered shop fronts and boarded up buildings overshadow the large brick bottle kilns that pop up across the horizon. “Stoke residents see their pottery and porcelain everywhere in the world, and their own city collapsing by the day,” says Ed Fordham, the local Lib Dem campaign organiser and former local councillor.

Slopes of two-up-two-downs dominate the landscape, many of the terraces built by factories for their workers. A uniformity that masks the political patchiness of the place. Hartshill, a middle-class area home to public sector workers at the hospital and university, is just a 15-minute drive from one of Europe’s largest council estates, Bentilee, which has over 4,000 homes. And there are aspirational residents of Hanley who vote Conservative.

Fordham is baffled by the inability of his party’s opponents to capitalise on the politics of the area. “I’ve never seen a party in opposition so determined to lose and a party who should be sweeping it up so unable to motivate the public,” he says, when I pop in for a cup of tea at Lib Dem campaign HQ – a backroom of the cosy Wheatsheaf Hotel pub, well-stocked with biscuits. His party is relying on middle-class voters and Remainers for support, running a former local councillor Zulfiqar Ali to fight for the seat.

The lack of a local candidate has plagued Ukip’s campaign. Smeeth, who represents the neighbouring constituency, accuses Nuttall of “political tourism”, claiming “he's using Stoke-on-Trent as a stepping stone”. The Bootle-born MEP is on his fifth attempt at being elected to Parliament. At a local Ukip rally with an audience of around 650 constituents on Monday night, there are mischievous digs about his Scouse accent, and he himself jokes about living in “the most famous house in Stoke” – he was recently accused of lying about his home address being in Staffordshire (which he denies).

“I’m going to get a blue plaque!” he guffaws when I ask about it. “Was Winston Churchill local to Dundee? Was Bonar Law local to Bootle? Was Tony Blair local to Sedgefield? Was Margaret Thatcher local to Finchley? The list goes on. What Stoke needs is a national voice, someone to shout about this town from the rooftops. And having another Labour voice in the wilderness is going to achieve nothing.”

But Nuttall’s lack of local standing isn’t his biggest challenge. After speaking to locals and activists from the main parties, I think it will probably be a low turnout that delivers a Labour win, if an uninspiring one. While many I speak to are wavering between Labour and Ukip – one 22-year-old office worker calls Labour “the lesser of two evils”, which sums up the tone – a lot seem to have switched off from the contest altogether. There is talk of “election fatigue” among Ukippers, and rainy and cold door-knocking days haven’t helped matters.

Nuttall is playing down the likelihood of a Ukip triumph. “Look, if I lose, I’ll still only be 12 weeks into my leadership. This was a long-term project,” he says. “The way it’s being written up as if this is the one – it wasn’t, it’s not even in our top 50 target seats, in fact I think it’s number 72.

“Many people are saying that I’ve taken a big chance,” he admits. “But you know, I’m a gambler!”

Meanwhile, the Labour operation is keeping Snell out of the spotlight. He is focusing on canvassing and being kept at arm’s length from the national press. Any more gaffes like his anti-Brexit tweets could blow the party’s chances of limping to victory. When I visit, its campaign office has a bunker feel to it – shelves of historic pottery and porcelain safely behind glass just as their candidate is shielded from prying journalists.

“We’ve turned the tide, but we’re not there yet,” warns Jack Dromey, the shadow labour minister and Birmingham Erdington MP who is helping with campaigning. “All by-elections are important but this is a landmark by-election . . . Stoke is a line in the sand. Can Ukip breakthrough in Labour’s heartlands or not?”