In the war against its biggest general election enemy - apathy - Labour has a secret weapon. He is 50 years old, Scottish, working-class, socialist, small, fat and ugly - his words, I hasten to add, not mine. Ian McCartney, the Cabinet Office minister, has been touring the country, along with John Prescott, to enthuse those disillusioned party members who suddenly matter so much for these few weeks.
The Prescott-McCartney roadshow has already played in 16 venues, the length and breadth of Britain, to packed houses. It is part serious politics, part gags. Which is where the unflattering description of McCartney comes in. The joke goes like this. Press officer phones minister to warn him that he has appeared in the News of the World. Minister puts down phone in state of anxiety and wonders how to reassure the wife. He tells himself: "Stay calm, no need to panic; if true, stress never again." He phones back press officer to ask exactly what the rag is saying. "It says you're an excellent minister, but you're also a socialist, and small, fat and ugly." Whereupon McCartney sardonically adds: "Just goes to show you can't believe a word the press says." He has been enjoying himself so much telling stories such as this, he says, that "at one stage I thought maybe I'd give up the day job and work in the theatre".
Comic talent aside, he insists his roadshows have served a deeper, more important purpose: to remind party workers that this election still has to be fought, no matter how strong Labour's lead is in the polls. Like Tony Blair, McCartney is worried about turnout: "A lot of people might not believe that the Tories can win, so the pressure's off. Well, the pressure can't be off: you can only win and win big if people will it." For McCartney, it's the 108th week of the campaign, because his main role for the past couple of years has been to act as a "bridgehead" between the party in government and the party in the country.
It has not always been an easy job, he confesses. "I've not yet got to the point where I thought I was the boy on the burning deck, but it has been a bit blustery on occasions." McCartney argues that party members are at last beginning to see real signs of social progress. Also, last autumn's traumatic fuel protests marked "a dramatic sea change" in party attitudes: suddenly people realised that not everyone loved Labour, and that a second victory would have to be fought for. No doubt. But is it not just a bit patronising to send out the government's two working-class lads, with their strong regional accents, to convince the troops that the Labour government isn't composed entirely of a smooth blend of southern yuppies?
But one should not focus too closely on the wrapper. Guess who made the main speech at McCartney's recent 50th birthday party? John Prescott? A very close friend, but no. Gordon Brown? No. Dick Caborn? John Reid? No. It was Peter Mandelson. This symbol of all that is most metropolitan, even swanky, about new Labour turns out to be one of the fiery Glaswegian's closest friends. Yes, McCartney admits, "they call us the odd couple", but they have been mates for more than 20 years, since they worked together for the Labour Party in the old days.
He claims they have more in common than people would think - even though McCartney calls himself a socialist ("yes, yes, I'm a socialist") while Mandelson most definitely would not.
Mandelson's absence from the Labour Party's headquarters at Millbank will clearly be felt, but McCartney insists that the campaign won't fall down without him. "If Peter had fallen under a bus, we'd have had to do it," he says (though he is confident that "Peter will find ways to make a contribution to the campaign"). So what unites them? Both were apparently very frustrated by the failure of the Labour Party to make any headway, both internally and outside, during the 1980s and 1990s.
McCartney describes as the "most debilitating thing" his time as a back-bench MP for Makerfield from 1987-97, when "the Tory party turned its guns on my community and tried to devastate it, removed its economic base". He is keenly aware that without power Labour can do nothing.
The style may be totally different, but McCartney and Mandelson are speaking the same language about Labour's second term. McCartney calls it "aspiration", Mandelson's term is "ambition", but both insist that this mode of social mobility is the key to what Labour must achieve next. As McCartney puts it: "We let Thatcher steal the word 'aspiration' and she turned it into a mean, nasty, no-society word. Well, aspiration is actually a socialist idea: you're aspiring for your community, you're aspiring for your nation."
In giving voice to Labour's latest big idea, McCartney has the advantage of having been a low-paid worker himself. He was a chef and waiter - known, he says without blinking, as DCM McCartney. What does the DCM stand for? "Don't Come back on Monday" - and he is hooting with laughter again. What his experience gave him was a passion to "get rid of low pay". He cites his work on the minimum wage as his proudest achievement, claiming that it was partly a matter of getting employers to realise that they, too, could benefit. "There was a 150 to 170 per cent turnover each year in the catering industry [which employs around 30,000 workers], so we had to build an economic case for employers being able to invest in the workers and get a financial payback for their investment."
If the campaign against low pay has guided McCartney's efforts in the first term, he is devoting himself to achieving more decentralisation in the next. He is "very committed" to regional assemblies, having moved a bill for a north-west regional assembly as long ago as 1980. "In the second term, we have to decentralise in an effective way," he insists, as part of regenerating communities.
But it is equally clear that, for McCartney, the culture of decentralisation must apply to the Labour Party, too. The current impression may be that No 10 has, in effect, neutralised both the National Executive Committee and the party conference as levers of influence on policy, but McCartney wants much more "decentralisation of decision-making". He envisages quite a shake-up for the Labour Party after the election, to make it "more effective at local level, more outgoing in terms of campaigning and recruitment of members, and in finding and developing candidates".
This doesn't sound like Millbank parachuting its favoured sons into plum seats and generally ignoring local activists. McCartney stresses the need for making better relations with the party, the trade unions and back-bench Labour MPs. Like Mandelson, he has long family connections with the party, since his father, Hugh, was a highly respected Scottish Labour MP and whip. Labour may need to be reformed, shaken up and challenged, but it is family, too.
Family, however, has brought McCartney his worst times as well as his best: 20 months ago, his son Hugh died of a heroin overdose at the age of 23. His body was found in a Glasgow tenement flat just a few days before Labour's party conference. For McCartney it was "a devastating loss, something you never get over", but he says he has to manage his emotions. "Some days you manage it well and can do an interview about it; and some days, the minute somebody mentions it, you have a black hole." Yet he has not shrunk from using his experience to try to wean others off drugs. He notes the irony of how he had been campaigning against drugs and solvent abuse long before his son became involved, and he is clearly perplexed as to what more he could have done to prevent it: "I did all the right things in trying to bring up my son in a drug-oriented society . . . and then he became involved, and couldn't find his way out of it." With characteristic bluntness, McCartney describes how he goes into prisons to talk to addicts: "They say 'Who's this prat?', and I say 'I'm a father and I used to have a son like you, but he's dead now'." Talking from the heart, he is much more effective than any ordinary minister because, he says, he has more credibility.
Here is a man, then, of passion, eloquence and strong party loyalties, whose personal network stretches from the newest of new Labour to deep into the party's oldest roots. We have touched on ambition as the watchword for Labour's second term, but what about McCartney's own ambition? In a sideswipe at some of his ministerial colleagues, McCartney denies he has a plan for his future: "You can't be a politician or a minister and not have personal ambitions, but the thing is to drive the ambition in the right way. Some people have ambition that eats them up, and they get frustrated because they have a personal plan." He claims that his own personal development plan is about ideas and issues, not a particular ministerial post. Certainly, he has a good range of street-level, common-sense policy successes to his credit: action on child abduction, dangerous foam furniture, new regulation of the security industry and the seizure of criminal assets.
If he stays on in the Cabinet Office and John Prescott becomes his boss there, they would certainly work well together, and maybe inject a bit of humour into the place. Not that all of his humour is politically correct. He recounts another of his "roadshow" gags: "I tell my audience that I became the youngest grandfather in the House of Commons and now have seven grandchildren. Why was that? Well, given the choice between a Labour party meeting or sex, I chose the latter."
He goes down very well with party members, and so he should. If anyone can be the bridgehead between new and old Labour, McCartney is the man. He can certainly convey No 10's message to the party - but can he convey the party's message to No 10?