Mandelson himself, who has been there and done that, arrived a few moments later. From the lobby of the Millbank Tower, an appalling piece of late- Sixties architecture in a wonderful position next to the Tate Gallery, we went to the first floor, where New Labour's new Communications Centre (Old Labour didn't have one) set up shop last month.
Readers, something extraordinary is happening up here. Something to make every loyal Tory's blue blood run cold. In a huge open-plan office, rather like the inside of an aircraft hangar, behind winking screens, sit two score young and very bright-looking girls and boys, busily plotting the downfall of the government and the accession of Tony Blair. Everything has just been thrown down, furniture, machinery and people. No unnecessary time was wasted on office ergonomics or pot-plants. This place has a purpose. On one machine a screen-saver scrolls the following message: "New Britain. New Labour. Young Country. Stakeholder Economy" endlessly. I am not joking. Boffins sit in corners E-mailing each other. Dave Hill, the prematurely grizzled "chief media spokesperson" of the party, sprawls over a desk in the centre of the room, gesticulating with both hands, speaking into a phone that someone has thoughtfully glued to his ear.
Over at Walworth Road, the decent plodders of the other Labour Party are sending out membership cards and amending rule-books, much as it would have done in Attlee's day. But in the Millbank Tower the Rapid Rebuttal Unit is rapidly rebutting government propaganda, collecting vast amounts of data with the help of an immensely powerful computer operation. If Hezza quotes Michael Meacher in a speech to Keele University's Gay Soc in 1983, he'd better get it right. If he himself has ever made such a speech, he'd better have kept a copy.
For many this is the apotheosis of Mandelson - a doomsday machine prefiguring the total destruction of all that they love and value about British party politics - with the boy from Hampstead Garden Suburb as its Doctor Strangelove. They see in it the ultimate triumph of communication over message, the tailoring of all important social objectives to the temporary fads and fashions of the politically unreliable middle classes.
A strong flavour of this appeared in the Daily Express this week, contained in a vituperative attack on Mandelson's book by that entertaining born- again radical, Roy Hattersley. "The Tory tactic", writes Roy, "is to pretend that New Labour is no more than an advertising gimmick and that the new leadership will smile and offer the voters whatever they seem to want". In his view not only is The Blair Revolution (Faber, pounds 7.99) an act of lese-majeste (in Roy's day, senior politicians did not embarrass their leaders by writing books about politics, apparently), but it is empty, lacking in direction and ideology, the work of a man who actually likes to be thought of as filling the "combined role of Rasputin, Svengali and Machiavelli".
It ain't really so. I have read a large number of such books in my time, written by practising politicians, and this is by no means a bad example of the genre. It is not at all remarkable that in some areas it pulls its punches - as over the future of the NHS - or that it pays elaborate compliments to shadow spokespersons, whose outdated policies it subtly undermines.
But in two instances it is genuinely daring. It explicitly rubbishes the John Smith alternative budget, which came out just before the 1992 election. This would have taken a lot of money away from a few who were not really rich, while giving very little to many who were genuinely poor. And Mandelson - unlike Hattersley - is interested in, and committed to, a large measure of political reform.
In a large back office, through which people troop remarkably democratically, I ask PM why Roy sounds so very cross with him. They had once, aeons ago, been pals. Peter campaigned for Roy to be leader in the early wilderness years, just after the '83 election massacre. He starts with a slightly ritual sentence about personal abuse suggesting weak arguments (actually I think it is quite possible to have both a very strong argument and, simultaneously, to abuse your opponent in the most offensive and satisfying way), but then warms up. "Roy has a very narrow belief in equality of outcome, which is the be-all and end-all. His means to do that by raising people's taxes and forcing them to send their children to identical schools". New Labour - as articulated by Mandelson - is not about these things. Of which more later.
I am brought tea. Peter himself drinks hot water. He doesn't take caffeine - and the Chinese drink hot water, he explains in a "what's so funny about that" voice. New Labour, New Age. Next we will be looking up Tony Blair's horoscope for next Spring: "Beware a tall, grey stranger".
I've known Peter Mandelson for a long time. We have many friends in common. When he was the chairman of the British Youth Council, I was the representative of the National Union of Students. We joined London Weekend Television as researchers on the same day, and were appointed producers of the cerebral Weekend World two years later - also on the same day. Now, this week, he seems to me to be happier than at any time in the last 15 years. Whether lounging on the green benches of the House of Commons as he awaited last Monday's Scott vote, or quizzed by John Humphrys in On the Record the day before, he seemed almost childishly happy. Was he?
"I am having a very good time. I feel much more comfortable, more confident than I have for ages. The reason is that with this book I've done something to back out of a situation that was beginning to get me down. Don't get me wrong," he goes on, "I'm immensely proud of what the Labour Party has done and of Tony Blair's leadership, and of my backroom role in helping to achieve all that, but it's like emerging from a chrysalis." Perhaps coincidentally, the front cover of this month's Prospect magazine depicts just such a Mandelsonian butterfly testing its new wings. It is a compelling image. I digest it as someone comes in to remind him about a youth meeting he is supposed to address with Mo Mowlam and an imminent "key candidates" gathering.
The problem for Peter is that he has been typecast. An innocuous question brings this response. "You could infer from that that I don't have any personal beliefs and that all I amount to is the sum of other people's beliefs. The claim has been made by my detractors [a very Mandelson word, that] in the party and elsewhere that I'm trying to make the Labour Party into a mirror-image of myself, something that doesn't stand for anything." Actually, I had been attempting rather clumsily to suggest the opposite. That in fact his own beliefs had been remarkably consistent, and that his new-found comfort reflected the party's shift Mandelsonwards.
This he likes. "It feels exactly like that," he says. "I have always occupied the same political ground. I have never wavered [another M word]." It's just that he wasn't in a position to go all ideological before. First, as communications director, he had to help Neil Kinnock hammer the Trots, professionalise the party and do what was necessary to improve its electoral chances.
And that, of course, is why he made enemies. The Tory press were fascinated by him and accorded him an importance that he now says was vastly inflated. Lazy journalism did the rest, and the myth of Mandelson was created. His colleagues were not best pleased.
OK, I say. But I saw you at the time, giving briefings and talking to journalists. You were very astringent. Don't you think that you said things then, in pursuit of the goal, that might have been better unsaid?
"We were under huge stresses and strains. Everything was bombarding us. There we were building a camp, starting with the foundations, while there were bricks and grenades and [laughs] rubbish pouring on us. Neil hated people who tried to have it both ways, who went straight out of meetings where a line had been agreed, and started playing to the gallery, especially in the early days, when it was all so uncertain. So I was uncompromising. It was my job to be uncompromising, to ensure that truth, decency and modernisation won." And the greatest of these is modernisation? "No, the greatest is truth," he smiles. Often he was just the fall-guy. "The leader would want something done, but would not want to do it himself. He didn't want to be caught doing it. Someone would have to do it for him."
But you hurt people, I whinge. "I wasn't hurting people for the sake of it, but because at that moment I felt I knew what needed to be done and people weren't pulling their weight. That could be very frustrating. I had a job to do. If, in the rush I was bruising, I'm sorry for it. But there it is.".
Now we come to what, for me, is the nub of it. Did you, as Mr Frank and Fearless, tell Neil Kinnock when he was being a dork? Would you tell Tony if he was behaving like a fool? "No. Even when I was at my least confident I would never, ever let it show. My cardinal principle was that the people I worked for should be supported. My job was to reinforce, even if I went out of the door feeling hopeless".
I saw this happen at LWT too. Peter was an ordinary producer (journalism was not his natural habitat), but could be an extraordinary companion. He has a personal charisma that I have never encountered anywhere else. More than anyone I know, he has the knack of making you want to belong to his gang. In an instant you are returned to the jungle anxieties of the playground, desperately wanting to be picked, to be confided in, to be joked with, to join in the exchange of snide witticisms. His bosses have all tended to become personal friends, charmed by an attentiveness and an empathy that would suit a lover. For those who retain his love, he is simply the most wonderful man to have around. They adore him. For those who lose it there can be a real feeling of loss and of betrayal. More perhaps than he realises. In the close world of politics, such relationships count for a lot.
Take Peter and Tony. Where others had advised Mandelson not to write a book, "one person gave the greatest support and never wavered, and that person was Tony Blair. He was the first person I went to and he said, 'It's a good idea - and it'd be good for you'." Later I observe that he and Blair are very close in age. "His birthday's in May and mine's in October". "Which day in May?" Peter has dodged far more agile interviewers than me. "I don't know," he says unconvincingly. Yeah, and I'm an Olympic athlete.
Passing back through lots of happy young Labourites busily rebutting things rapidly, I can't help thinking that - whatever Roy and others say - if I was Tony then I'd want Peter by my side. Leaders these days need all the help they can get.