Labour marked its worst performance in more than 50 years when voters went to the polls in Barnsley in May, but 100 days on from those seismic local elections, the political landscape has shifted drastically.

Could the South Yorkshire town, where Reform UK reaped the benefits of dissatisfaction with Labour, prove to be a test case for whether the governing party has turned the tide?

Labour had run Barnsley’s council since its inception in 1974, but was left with just 11 councillors after Reform triumphed with 42 seats.

“I knew that it would be the most challenging set of elections that we’ve ever faced in Barnsley’s history,” said the councillor James Higginbottom, the new Labour group opposition leader. “What I didn’t necessarily expect was the scale of the Reform victory.”

Catastrophic results in places such as Barnsley were a catalyst for Keir Starmer’s resignation. He has been replaced as prime minister by the former mayor of Greater Manchester Andy Burnham, who won the Labour leadership uncontested after a landslide byelection victory.

Meanwhile, the Reform leader, Nigel Farage, is facing scrutiny over his financial affairs. While he was decisively re-elected in Clacton on Thursday, after he called a byelection in protest over a parliamentary standards investigation into his financial gifts, the contest was largely viewed as a sideshow after other major parties declined to stand. The parliamentary standards investigation has now resumed.

Labour is now ahead in the polls for the first time since March 2025, with a YouGov poll on Monday giving Labour a two-point lead, at 24 points to Reform’s 22.

Many in Barnsley used their vote in May to punish Starmer’s government, and while almost everyone the Guardian spoke to there this week said it was too early to judge the Reform council on their record, the new national political picture appears to be enticing at least some back to Labour.

In the town of Penistone, Richard Riding, 71, a retired HGV driver, said he was normally a Labour voter but had backed Reform in May “just for a change”.

“The current government were in a total mess,” he said, “and we’ve had a lot of problems.”

But he is no fan of Farage. “If you think the country’s in a mess now with Europe, it’s going to be totally destroyed if he takes over.” he said. “[Burnham] did a very good job in Manchester so let’s see what he can do now,” he added, saying he would vote Labour next time.

Labour’s Barnsley council was not your usual local administration. It had won both the Local Government Chronicle and the Municipal Journal (MJ) council of the year awards in 2023, becoming the first local authority to win both titles in the same year. In February, Barnsley was named in the top 10 most productive councils in the country, coming in seventh in the Impower Index, published by the MJ.

While in many towns people felt as dissatisfied with local administrations as they did with national government, Barnsley had launched a number of pioneering initiatives, including “health on the high street”, making it the first local authority to bring hospital services into the town centre, and free bus travel for under-18s, a version of which Burnham has since adopted nationally.

Barnsley parents also received free school uniforms for their children in a scheme that saved families about £2.5m in a year. It has already been scaled back by Reform. (Reform’s council leader and local party chair did not respond to interview requests.)

Despite this innovative work, voters still punished Labour at the ballot box. “By and large, people were saying to us: ‘I like what the council’s doing’,” Higginbottom said, “but that national stuff, we just couldn’t overcome that.”

Martin Harvey, 75, who worked in engineering, said he “has been Labour all my life”, but concerns about immigration meant he turned to Reform in May, and plans to stick with them.

“I’ve just been watching on TV, GB News, and I don’t know, locally everything around here seems to be fine,” he said, but added: “Politics in general, I’m frightened, I am frightened of what’s happening. It’s just frightening how many boats are coming across.”

Jessica Morgan, 31, a retail worker, was always a Labour voter, but she voted Reform for the first time in May. “I’m still happy with that decision,” she said.

“I just want the roads to be fixed, the potholes to be filled,” she added. “Labour were just cushty, because Barnsley has always been Labour. Even my grandad, he used to be a pit miner and he’s always voted for Labour, but this time … no. He also voted Reform.”

But there are early signs that some voters are thinking of returning to Labour. In the Penistone East ward of Barnsley, a council byelection has been triggered by the resignation of a Reform councillor. In May, Labour won two of the seats that were up for grabs, and Reform won the third. But a Labour source said they were “confident we will win” the third seat on Thursday.

Higginbottom said: “I think that will be a good barometer as to where we are; are we reconnecting with voters who in May didn’t feel able to put their trust in us?”

Labour has spoken to more than 1,000 voters in the ward so far and aims to double that by polling day.

“I’m not saying they’re rushing out to suddenly say: ‘Yeah, we love Labour and we’re going to be voting for you en masse’,” Higginbottom said, “[but] some are willing to give us a fair hearing, and to listen to what we’ve got to say.”

Marie Tidball, the Labour MP for Penistone and Stocksbridge, said she had “definitely” noticed a shift in voter attitudes while campaigning for the byelection, in comparison to May.

“It really does feel like it’s cut through in terms of Andy being boldly and confidently and authentically Labour once again, and I think people do seem to really identify with him as a person in a very powerful way,” she said.

Keith Hibbert, 67, a retired project manager in engineering, voted Labour in May, as he “wasn’t convinced yet” by Reform. His wife, Jill, a former nurse, also 67, switched to Farage’s party based on “just the manifesto”, having always voted Labour in the past. Both are cautiously optimistic about Burnham’s leadership.

“I think they’ve given Labour a new leaf, because there’s a new face, a new personality,” Keith said. Jill added she would probably vote Labour again.

Dan Jarvis, the MP for Barnsley North, said: “Reform did well when people could only judge their promises. Unfortunately for them, their actions will now be judged too.”

Stephanie Peacock, the MP for Barnsley South, said: “It’s still in early days, but I’ve seen already that residents across Barnsley are more open and willing to give the Labour party a hearing.”

She said one woman who had previously been “pretty anti-government, and pro-Reform” had told her she would vote Labour with Burnham as prime minister. “It’s not just the PM’s focus on tacking the cost of living,” she said, “it’s the government’s more hopeful and positive tone that is cutting through.”