Steve Turner is sitting on the sofa in his south London home and he’s sick of it. For nearly a year, the Unite assistant general secretary has been hamstrung by lockdown, unable to properly do his day job of negotiating on behalf of its members in workplaces up and down the land.

“I’ll go into the office a couple of days a week, and there are particular meetings, but other than that I’ve been on this settee so much it’s now got a dent in it!” he says. “It’s driving me nuts because I’m a social person, I want to get out and I want to interact with people.”

As Unite’s most senior official with specific responsibility for manufacturing, the need to interact with employers has never been stronger as job losses loom post-furlough. Turner’s rare recent forays to factories have included GKN and Liberty Steel, both threatened with closure. And when high-skilled jobs are on the line, Zoom doesn’t cut it.

“It’s looking someone in the eye, just sitting down and having a straight conversation. People talk about ‘beer and sandwiches’, but that’s where a lot of our business is done, in the evenings, in a coffee shop somewhere, just having that break and building a relationship. Because a lot of this is about trust – believing that people are being straight with you and being confident in the person that you’re negotiating with, for them and us.”

Being straight with Unite’s members is what Turner hopes will help him win the race to be the next general secretary of the UK’s second largest union. With Len McCluskey stepping down after 11 years in post, and the election to replace him due this summer, it’s undoubtedly the end of an era.

Unite has played a key role in both the trade union movement and in the Labour party, which has relied on its financial and political muscle for more than a decade. McCluskey, whose staunch support helped Jeremy Corbyn to defy the shadow cabinet “coup” of 2016, is such a high profile figure that even members of some other unions think he’s their general secretary.

Turner, who was McCluskey’s campaign manager for his three general secretary election victories, is seen by many as the favourite to succeed him. Having last year clinched the nomination of the crucial United Left grouping, which dominates every level of the union from its executive to its regional officers, he’s certainly in a strong position. He also has extensive links to the union’s retired members and its Unite Community arm, both of whom get votes.

But while Turner shares many of McCluskey’s politics, he’s at pains to point out he would be a very different kind of union boss. His Charter for Change campaign is aimed at reconnecting Unite with its members, expanding its reach in new industries and shifting away from Labour’s endless internal warfare.

“I’m a close ally of Len’s and have been for years. We do have a very distinct and different style though. I’m much more collegiate, much more of a team builder, and much more into decentralising decision-making and pulling people together to make better decisions. When you engage with people in an open way in which people feel free to contribute and to engage and to disagree, we come out of those meetings stronger.”

Turner’s belief that compromise is not a dirty word, and that engagement is better than confrontation, was underlined when he played a key role in talks with the government last spring on how to avoid a huge spike in unemployment caused by lockdown. He was part of a small group of union officials – himself, the TUC’s Frances O’Grady and Kate Bell, and Prospect union’s Mike Clancy – that met Rishi Sunak and Treasury officials to help draft what became the furlough policy.

“People need to know this wasn’t a gift from government. It was a real struggle very early on, there were many hawks inside the cabinet that didn’t see a role for government, even in those circumstances, for intervening in the labour market, and becoming effectively the employer or at least the paymaster of last resort.”

Intriguingly, Turner says the furlough idea grew out of discussions he and others had been having for some time with government about possible German-style, short-working provisions in the event of a no-deal Brexit, to help firms keep staff on the payroll despite the hit to trade.

Turner says that furlough and the self-employed scheme, which the unions also helped negotiate, still have big gaps in provision. “But for all of its faults, and for everyone that missed out in that protection, I always think that you shouldn’t lose sight of your victories on your journey, “ he says. “Because that scheme protected over 11 million working people and their families through one of the deepest crises that we face outside of a war.

“The Tories are in power and the Tories hold the pen on decisions. I’m engaging with [business secretary] Kwasi Kwarteng now on GKN and Liberty Steel. I’m in the room, I’m at the table, I’m not outside lobbing bricks over the wall. I see my role as doing whatever is necessary in order to protect the long term interests of our members and their families and the communities that we live in.”

Unemployment, and the fear of unemployment, is something Turner knows all too well. “I’ve been unemployed, I walked six miles to get a construction job once [from his home on the now demolished Heygate council estate in Elephant and Castle] and the guy never turned up.” He first joined the T&G union [Unite’s forerunner] as a 19-year-old bus conductor, and has worked at every level from shop steward to branch secretary and national official.

That long and broad experience could be crucial in the general secretary race, together with his ability to unite those who don’t share all his politics. Turner’s ability to unite the different parts of the Labour movement has seen his campaign get early endorsements from MPs like Jon Cruddas, Momentum founder Jon Lansman and the Communist Party of Great Britain. Former shadow chancellor John McDonnell is understood to be a supporter, though he has not declared so publicly.

Turner’s approachability is perhaps summed up by his love of Millwall football club, where he and centrist Labour MP John Spellar sit just 20 seats apart in the Dockers’ Stand. “I’m miles away from John politically, but I’m a personable character. We’ll have a chat and a laugh when he’s at a match. He’s a political foe but he’s not my personal enemy.”

Another famous trade unionist who wore his Millwall links with pride was the late RMT leader Bob Crow. He and Turner were “good mates”, so much so that he helped carry Crow’s coffin on the day of his funeral. On the anniversary of his death recently, he and the Crow family laid a wreath at Millwall’s Den stadium, where a portion of his ashes are buried.

“I miss Bob, I spoke to him the night before he died, we were planning to go to a match. He said ‘I’m not feeling too well, I’m getting an early night’.” The following day the rail workers’ leader suffered a massive heart attack, and died at the age of just 52. Yet despite his hard left image, Crow was always someone employers knew they could “do business with”, and was hugely effective in growing his union and getting members better pay and conditions.

Although Turner’s style is different, the influence is obvious. “We have a [£40m] strike fund. We have led a climate of confidence for our members to stand up and feel the union has their back. That’s why our members join, it’s not the big conflicts or the politics, it’s that day to day role that the union has that puts its arm round our members, whether it’s pay negotiation, health and safety, a grievance or a disciplinary.”

The return to a focus on the workplace rather than party politics is a key part of his campaign. “This is not a political playground. I had a couple of invites this morning to do a Labour Left group hustings, and I said why the f*ck do I want to do that? I’m running to be general secretary of my union, not to be leader of the Labour party. I’ll do hustings, but with our members.”

One rival in the race to succeed McCluskey, fellow assistant general secretary Howard Beckett, certainly has a more confrontational approach to Labour’s internal workings. Beckett has been vociferous in meetings of Labour’s National Executive Committee (NEC), even leading an online “walkout” at one point in protest at what he called Starmer’s treatment of the left and unions. He has warned the Labour leader against trying to “dump the pandemic fallout on the working class”.

Under union rules, candidates for general secretary are not allowed to criticise each other, but it’s clear Turner does not share Beckett’s approach. While he is “disappointed” Starmer appears to have backed off the radical 10-pledge plan that won him the leadership, and disagrees with him over the removal of the whip from Corbyn, he believes criticism is more effective if done privately.

“I’ve always felt we could get a solution to this [Corbyn getting the whip back]. But the longer it goes on, the more entrenched it becomes on both sides. It’s like a war of attrition going on, and it’s going on in public. That’s not helpful to the party, it’s not helpful to Keir, it’s not helpful to Jeremy and it’s not helpful to me as a trade union leader or our members.

“People don’t vote for a divided party. Or a party that’s contemplating his own navel. Sometimes it’s right to shout. But on some occasions diplomacy is best done privately. Look, Keir wasn’t my preferred candidate [he voted for Rebecca Long-Bailey]. But I’m a socialist, I’m a democrat, and the reality of it is he was elected by the vast majority of our members that voted.

“We didn’t even convince our own members to come on a journey with us, in terms of the political program that was being laid out by Jeremy, Becky and that entire team. We didn’t win the argument inside our own union. We won it amongst the politicos and that group that loves to talk to themselves. In the chat rooms of Twitter, they’re always ‘winning’. But in the real world out there, where 99.9% of our members reside, they’re not.”

Turner says the perils of left-wingers undermining Labour councils are real. “I want to see Labour councillors elected on May 6. I want to see Labour mayors. And it frustrates me, it angers me sometimes, that some of the union’s campaigning right now is pitched against our Mayors, against Sadiq and Andy Burnham. What’s that all about? I find that incredible that we would do that.

“Trying to get this purist Left, I find incredibly dangerous. We’re fighting the rise of the far right and that narrative of hate and division in society more generally. We are trying to pull the Left together to create a vision of a better Britain and we’ve got this purist debate that’s taken place, pitting good Left comrades against good Left comrades, because they don’t sign up to a particular way of thinking on a particular issue.

“That purist argument, you’re a class traitor if you don’t sign up to something is just beyond belief, that’s not my Left. I’m an inclusive, tolerant, Left.”

Turner is up against not just Beckett but also leftwing national organiser Sharon Graham and centrist Gerard Coyne, and he fears that some candidates will want to use Labour factionalism to dominate the election.

“That conflict that’s there in the Labour Party at the moment, I fear will come into Unite, and I fear that some candidates are trying to bring that into Unite. And they’ll want it to be more about a relationship with the Labour Party than our relationship with our members. At the end of the day we’re an industrial trade union, people pay their dues to be protected at work. That’s where I’m pitching, it’s not because I’m apolitical, far from it. But that’s not where our union needs to be in terms of the centre stage.”

Candidates for general secretary need to get 174 nominations from union branches to stand. But Turner warns that with one centrist candidate against three leftwingers, in a first past the post election, there is a danger that the left vote will split and Coyne – who came within 5,000 votes of beating McCluskey in 2017 – will win.

“If everyone’s on the ballot paper, if there were a four way split, then that’s pretty much an open game. And who knows what the outcome of that would be. I think the centre vote would hold up because that’s a core vote, if that candidate played their cards right and ran a good campaign and not a negative campaign, absolutely I can see them getting 60,000 votes. And if we had the same turnout as last time, there ain’t enough votes to go round on a straight three-way split to defeat that.”

Turner’s friends have been amused of late to see suggestions from some critics that he himself is somehow a centrist, simply because he is a pragmatist. A former member of Militant, the Trotskyite grouping whose members were eventually expelled from Labour by Neil Kinnock in the 1980s, one colleague remembers his private email address included the phrase “MillwallMilitant”.

It’s a past he doesn’t shy away from. “I was a member of Militant. I was on the London executive,” he says. “I used to walk Ted Grant [Militant Tendency’s founder] home to his council flat in Hackney Wick because he was under constant threat of attack from the National Front. But when Militant split and Peter Taafe formed what went on to become the Socialist Party, I never went. I stayed inside the Labour Party because I’ve always seen the Labour Party as the vehicle for transitioning our economy.”

Transitioning the UK toward industries of the future is one of Turner’s big passions, precisely because it guarantees well paid, skilled jobs for Unite members. He is keen on sustainable aviation fuels (SAFs) to help secure work for members who work at Airbus, Rolls Royce and Heathrow, as well as working with firms to shift battery-powered car production to the UK. He’s also evangelical about nuclear power and its role in cutting carbon emissions, as well as the nascent hydrogen industry.

One telling moment came after a Brussels meeting of the European Trade Union Confederation, when he chatted with a German colleague from the IG Metall engineering union. “We were having a few beers and he was talking about the auto industry in the 1980s. He said, ‘I remember all your strikes trying to keep robots off the lines. I’ll tell you the discussion we were having: who is building those robots?’ And that did stick with me because that’s true, we have to be two steps ahead of the game, if we want to secure jobs for the next 20, 30, 40 years.”

Turner’s worldview, and his vision for the future of the union, is also grounded in his own working history. As a young man, he worked for a council re-turfing a local park. “I was having a chat with the old groundsman who had been there for years. I said ‘when are you laying the paths?’ and he said ‘You never lay a path straight away. You leave it for six months and watch where people walk. Then you lay your path.’

“And that has stayed with me around everything that I do, particularly on union structures and new groups of workers. We’ve got to be relevant to new groups in the economy, the digital, the gig economy. None of it will be easy, but it wasn’t easy when we were standing on a soapbox without a mobile phone or an office in the 1880s. We had to inspire people and had to motivate them to collectivise. We have to do that all over again.”