The coffee table in the office of Len McCluskey, an assistant general secretary of Unite and the best-known of four candidates in the union's leadership election this autumn, is empty but for a small chess set, the pieces neatly arranged ready for a match. I ask if he plays often. Oh no, he says, as if he's barely moved a pawn. "But perhaps," he adds light-heartedly, "Derek should have made me play to decide on the candidacy."
It is an affectionate-seeming swipe at the current joint general secretary Derek Simpson, who chose to back Les Bayliss as his successor when he retires in December. McCluskey is the preferred candidate of Unite's other general secretary, Tony Woodley, with whom the successful candidate will have to work as "general secretary designate" until Woodley retires a year later in December 2011, after which - finally - there will be only one.
The change, for many, cannot come soon enough. Simpson and Woodley have shared the leadership of Britain's largest union since it was formed through the merger of Amicus and the Transport and General Workers' Union in 2007, but they have disagreed on many things besides their successor. McCluskey tells me that his campaign is going well - "I am humbled by the response from all sectors of the union" - but members everywhere have expressed frustration and anger that the integration of the union has not been properly completed.
“Ex-Amicus and ex-T&G shop stewards are now working well together and the benefits are clear," he says. "But at the top of the union, we still appear to have two different approaches, and that won't change until we elect a single general secretary." A self-confessed member of the union's left, McCluskey is standing as the "unity" candidate and insists that, if elected, he will drive through the integration in "a matter of weeks".
He appears unfazed by the prospect of leading roughly 1.7 million members through one of the hardest periods for working people in living memory. As the coalition government's axe continues to fall, Unite members - a quarter of a million or so in the public sector, the rest in the private sector - are at the sharp end of the cuts. As jobs go, so do members; union finances feel the strain and recruitment gets ever harder.
“I relish the challenge. But anyone who tells you that they can run such a diverse union from an office in London is talking nonsense. You need a collegiate approach to leadership. In 2007, our members voted for a union that could be a powerful, progressive force for good in our society: it's now time to deliver."
McCluskey's talk of conciliation and co-operation is not what you might expect from the officer responsible for Unite's industrial strategy, who has earned the epithet "Red Len" through his part in the union's highest-profile action over the past year - the ongoing dispute with BA (the negotiations are now being headed by Simpson and Woodley). The airline's chief executive, Willie Walsh, wants "unconditional surrender", McCluskey tells me. "He has made the kind of attacks on decent people that should not be tolerated in a civilised society and, if only the media focused on them, would shock people."
Newspapers have had rather more fun recalling McCluskey's history as a shop steward on the Liverpool docks and casting him as a throwback to the 1970s. "I almost wear that as a badge of honour," he says, robustly. "The media are constantly trying to rewrite history. We are all supposed to believe now that the 1970s was a horrible time. It wasn't at all. It was a time of great advances for working people, such as equal pay and health and safety legislation. If the papers want to accuse me of having not moved from my original principles, then I happily plead guilty."
So is he, as they say, bent on rushing his members out on strike? "I've been representing people for 40 years and conclude agreements with companies 90 per cent of the time, but on the basis of being prepared to fight when needed. If getting involved in a fight such as with BA means
I am vilified in the press, that doesn't bother me. The only thing I'm interested in is what my members think of me."
Criticism also comes from closer to home. McCluskey's fellow assistant general secretary and leadership candidate, Gail Cartmail, has accused him, Bayliss and Jerry Hicks (a repeat contender, having unsuccessfully challenged Simpson for the leadership in 2008) of representing an old guard of "white, male, pale and stale" officers. McCluskey puts his hands up to the first three, but denies being stale.
“I have the same burning desire that I had as a young steward on the docks - and that's to advance the cause of working people." And he reassures himself that he has the support of many senior women officers in the union and the chairs of all the equality committees. "I learned from an early age that an attempt to discriminate against any worker is an attack on all workers."
The ideological depth of the latest attacks has, he says, "taken even my breath away". Since May, he claims, the government has targeted shop stewards' facilities with the aim of making the unions less effective and thereby making it easier to roll out the cuts agenda. McCluskey says he would welcome the chance to explain to David Cameron why he's got it wrong, but accepts that it's not enough to oppose the cuts. "We have to offer an alternative, and we have one - it's called the People's Charter, which is both Unite and TUC policy."
In what McCluskey calls "a watershed moment" for the TUC and its leader, Brendan Barber, the need for an "alliance of resistance" against the cuts will dominate the annual conference - and, he suspects, the Labour conference, too. Unite, one of the party's biggest union backers, is supporting Ed Miliband for the leadership, but McCluskey sounds a note of warning.
“Everywhere I go, I am asked why we pay them so much money. After 13 years of New Labour, British workers are still the worst-protected in Europe. I'm not for leaving the Labour Party, but I'm not going to continue the line of just handing over millions of pounds without it demonstrating it is changing." He envisages unions and Labour MPs joining forces to reclaim the party "right up from the roots", to make it "our party again and get it back into power - I can see that happening in maybe three years."
If he himself comes out on top when the result of the ballot is announced in late November, McCluskey, now 60, will serve a single five-year term. He sees this as an advantage. "I will be able to take some of the difficult decisions that need to be taken without worrying about re-election." But his greatest asset, he argues, is his long experience representing members since first becoming a shop steward aged 19. "I've almost got to say: 'This is no time for a novice' - but maybe I won't," he interrupts himself, beginning to laugh. "It didn't work for Gordon Brown!"
McCluskey is sober about the struggle ahead. "I should have said at the start that I don't have a magic wand to right all the wrongs." He is, however, brimming with what he considers to be the most important thing trade unionists can have - confidence - and a belief that his members, like the pieces on his chess set, are ready for battle.