Nigel Farage was midway through his walkabout of Waltham Abbey when a hunting horn loudly sounded on the Essex market town’s pedestrianised high street. “Oi oiii!” exclaimed the owner of Ouch Tattoos, Rob Chillingworth, putting down the instrument and reaching out a welcoming hand to the approaching Reform UK leader.

For Farage, this was the latest stop in a midweek tour of half a dozen towns in Essex, where more than 1m county council votes are up for grabs. Barring breakthroughs in Wales and Scotland, going from having a single councillor here to taking power would be one of Reform’s biggest achievements in Thursday’s polls.

While encounters such as the one between Chillingworth and Farage reflect warmth towards Reform among many here, the campaign in Essex is also a demonstration and a test of Reform’s self-professed professionalisation when it comes to ensuring the party gets its vote out more broadly.

Mobilising passionate core supporters in what are traditionally low-turnout polls – as well as repeating a “blue ocean” strategy of casting a wider net for first-time voters and those whom other parties may have given up on – is where the party’s new machinery and organisation come in.

Farage-led predecessor parties such as Ukip often faltered but Reform sees this set of elections as a showcase for a newer, sleeker approach, bringing together the energy of an army of activists with new technology and a clinical approach to handling voter data, which is being harvested with the next general election in mind.

This includes an “air war” – the term used for efforts to gain media coverage and attention using adverts – involving mailshots and leafleting as well as targeted Facebook ads, with nearly £100,000 spent on the latter in the last 30 days, according to Meta’s Ad Library.

For the first time in a major election, the ReformGo app will aid thousands of the party’s activists as they knock on doors. While other established parties have long used their own versions to collect data on voters, Reform is only just catching up.

“It’s a very comprehensive app and we can see week by week it’s improving, data refinement, ease of usability on it,” said one branch official in Essex. “People can see the doors they need to knock, list responses – anywhere from ‘I’m voting for you’ down to ‘go away’ or ‘I’d like a garden board please’.”

Activists hope data gathered during the local elections will prove invaluable in shaping Reform’s campaign strategy for the next general election. “The capture of that voter intention data is going to help us going forward,” the branch official added.

Other Reform targets such as Birmingham city council would represent significant wins on Thursday, but few places would be as politically emblematic as Essex, which until recently has been considered Tory heartlands.

At a council level, a win would mark the capture of a local authority where the Conservatives have primarily been the party of power since the body’s foundation in 1974. Aside from controlling a council with a £1.2bn budget, it would give Reform another political foothold – allied to Farage’s Westminster seat in Clacton – in a part of the UK that had some of the highest votes for Brexit. Victory here would also lay the ground for a possible general election cull of Essex Tory frontbenchers including Priti Patel, James Cleverly, Alex Burghart and even Kemi Badenoch.

In Reform’s gleaming new office in Millbank Tower, volunteers from around Britain are taking turns to staff phone banks. Their call list is informed by another app, ReformPro, which is used by senior activists pounding the streets of Essex, Birmingham and northern towns and is more plugged into electoral register data.

“We have to broaden our vote and the app is a big step towards doing that,” Farage said, pausing in Waltham Abbey after a visit to a pie and mash shop before a meeting that night with 80 local candidates.

Reform has previously been compared to Italy’s Five Star Movement, a pioneer of digital, anti-establishment populism, but Farage has recently pointed to an unlikely source of campaign inspiration: the Liberal Democrats.

“They’re really, really good at picking an area and saying ‘right, this is good for us,’ and then they’re very ruthless about their data, how they manage it, how they protect it,” Farage said. “It’s the Paddy Ashdown school of thought. When you win significant local representation, you build upon that and then target areas for the general election.”

Gawain Towler, a Reform board member, said the party was learning from past mistakes. “If things are not working well then it’s getting picked up much faster. In a place I was in recently, the Labour letter was arriving two days late for postal voters. We used to make that error,” he said.

But critics of the notion that Reform has professionalised point to the elephant in the room: the failures of the party’s vetting process. There has been a drip-feed of allegations of candidates making racist or offensive comments in the past.

The latest batch of Reform candidates singled out by Hope Not Hate included one in Gateshead who had called for a “white Britain” and said Keir Starmer should be shot. “The amount we have found has astonished us,” said Joe Mulhall, the organisation’s director of research. “Despite what they say about their professionalisation, clearly they continue to have a systematic problem.”

Reform may know more about which voters to target, but gaps remain once they get to the doorstep. Candidates are able to answer questions about immigration policy but are less up to speed on health policy, not helped by the lack of a frontbench spokesperson on the topic.

“They’ve beefed up their press team and are good at making a splash,” said a spin doctor from a rival party. “But when it comes to, for example, negative stories about their candidates, it’s not clear what they are doing. Sometimes they seem to want to rebut allegations. At other times they only eventually get there, or try to pretend it’s not happening.”