He returns to this theme several times over the next hour. In fact it serves as a reminder that the Government's public image has not been at all positive during the summer break when Mandelson and Prescott have minded shop while Tony Blair took three weeks' holiday. He may be a master of media manipulation, but these weeks have not gone smoothly.
In the room adjacent to what was Michael Heseltine's palatial office (now used as a meeting place) an explanation is advanced by the Minister Without Portfolio. He believes politics is operating on two levels: "One is a big picture, with issues such as the Budget, the European Council at Amsterdam and the G8 summit at Denver" - which gave Labour its flying start. "But the moment August begins we're swamped with trivia. The media has the same amount of airtime to fill, the newspapers still have column inches to fill; small things are magnified and become big things." Meanwhile, the Conservatives "exaggerate, spin and manipulate". That's the other level.
This is a little rich, perhaps, from the man who must have done some spinning of his own in Augusts past. "Yes, I have," he says. "I'm not complaining about it. I'm observing it, but the fact that the Conservatives attack us in such an incompetent way is, frankly, grist to our mill." This is vintage Mandelson, turning an admission into a vicious attack on the opposition in a trice.
In the sweltering heat the minister has taken off his jacket and he looks cool as he rejects the notion that his August has been a PR disaster and contests each charge of government incompetence, U-turn or mismanagement. It was impossible, so he says, to avoid the bizarre situation in which he and Mr Prescott appeared to be at odds over the roof of the Millennium Dome. He claims that the Deputy Prime Minister was simply responding to newspaper articles and, before a final decision to prefer Teflon to PVC for the surface of the roof had been taken, he had no option but to comment on the situation as it was then. Other problems, such as the turmoil created by the suicide of the Labour MP Gordon McMaster, are not relevant, he says, because the Government had no power to control them.
August may not have been a seamless example of media management but it has undoubtedly introduced Mr Mandelson to a wider public. This is partly accidental and partly deliberate. He has clearly attempted to raise his profile before Labour's National Executive Committee elections. He is standing this year and ballot papers have recently been dispatched to party members. This dictated the timing of his Fabian Society lecture 10 days ago - though it seems to him to have been longer ago than that - about "social exclusion" and the new co-ordinating committee to combat deprivation. Few measures could be better calculated to appeal to the rank and file. Mr Mandelson has been to several regions and popped up in Scotland. He has even appeared on the front page of the Times holding a smiling child.
The emphasis on Mr Mandelson's rapport, or lack of it, with Mr Prescott has been less welcome. While the Minister Without Portfolio has given endless interviews, Mr Prescott, who is senior in rank by some margin, has sometimes completely disappeared from the radar screen. He reappeared on it in "Crabgate" last Monday when he looked at a crab in a jar and called it Peter. This was promptly taken by many media commentators as proof that the Deputy Prime Minister resented Mr Mandelson's ubiquitous presence.
So were John Prescott's comments helpful? The emphatic if not entirely convincing reply describes them as "fun". The minister, who is now playing with a blue paper-clip, says: "John and I have been reacting to these stories with belly-laughs. In private we have enormous fun at the journalists' expense. As far as John Prescott and I are concerned, we are working well in government. I see more of him and work more closely with him than any other member of the Cabinet. I have been supporting him in what he has to do in the summer, and he is supportive of me, but the press likes to write the same old story about John and me which is based on a difficult patch in relations when he found himself on the wrong side of Roy Hattersley and Neil Kinnock. That was 10 years ago.
"Since then I have supported him for deputy leader of the party, I have campaigned very hard for him in key seats, helped design his general election role, and worked very closely with him in government."
The admission of that uneasy spell in relations is interesting, the more so because Mr Mandelson admits to similar difficulties with the Chancellor, Gordon Brown. Here the history is different; Mr Prescott and Mr Mandelson come from opposite ends of the Labour movement, but Mr Brown and Mr Mandelson were once close. Peter Mandelson's role in the leadership election in 1994, when he backed Tony Blair and not Gordon Brown, is said to have caused bad blood and his response admits the truth of this. Any strains have been "entirely resolved", he says, before moving sharply on to the counter-offensive. "I wouldn't believe what you read in books and newspapers because it is laced with a lot of misinformation, and the noise of axes grinding. It is no secret that Gordon was disappointed when he did not stand for the leadership in 1994, and some people around him were looking for a scapegoat to blame. I was a convenient target. I have never allowed that to colour my view of Gordon." On the charge of treachery, of having switched sides, he says: "Gordon knows it is complete rubbish."
"In the absence of policy differences some of the media will cast around for other sticks with which to beat us," he goes on. "We don't present many targets to the media, therefore they clutch at any straw. The press thrives on sensations of conflict, on so-called gaffes. That's the sort of easy, simple journalism that passes as a substitute for good, old-fashioned investigative reporting."
Peter Mandelson does admit to having enemies: "I have been at the cutting edge of change in the party since 1985. I've had to handle that change. In many cases, I've been its public face in the media. In the early days there was conflict. Some were very uncomfortable about what was happening and I became a target for them. Not because of personal dislike, but because of the changes taking place and the way I had become associated with them."
He also admits to a desire to alter this relationship with the party. For two years he has been trying to ditch the image of media manipulator and spin-doctor, and to recast himself as a heavyweight politician. First he wrote a book, The Blair Revolution, with Roger Liddle, which was his blueprint for Blairite government. Now he sees his NEC campaign as a bid for "clearer more independent standing in the party - not because I want more power, status or titles, but because I want to be more accountable to the party for the power I allegedly exercise".
His desire to emulate his grandfather Herbert Morrison, who became foreign secretary in Clement Attlee's second administration, and who presided over the Festival of Britain in 1951, is illustrated by the presence of a small print of Morrison on the office mantelpiece. (He was a lot tubbier than his grandson.)
In the few months since Labour came to office Peter Mandelson has established a powerful presence; onesenior civil servant describes him as one of five people who run government. The NEC elections will reveal whether he can broaden his power base. One theory is that his visible presence in London this summer will boost his prospects because most party members vote for names they recognise, and Mr Mandelson's has hardly been off the front pages. Another is that his prospects, which were very good, have suffered from over-exposure and the appearance he has given of trying to supplant the Deputy Prime Minister. Although he claims little can be done to influence the outcome of the vote, his schedule on Friday afternoon included a meeting with two close political allies to discuss his election strategy.
Despite the calculated venom he directs at sections of the media, Mr Mandelson cannot rid himself of the compulsion to be at the centre of presentation as well as policy. His mastery of the message is still an invaluable political tool, and, besides that, he revels in it. At one point during our interview he left the room to take a telephone call. When he returned he explained that he had been consulted about a Conservative- inspired story, due to appear today, about Mr Prescott.
And, as we left, the Minister Without Portfolio dropped his hostility to the media, cheerfully signing a photograph for our photographer. It showed the stretch of wasteland where the Millennium Dome will take shape and, in the forefront, a large crab.Reuse content