For a Labour leadership contender who insists his politics is all about the future, David Miliband is acutely concerned about history repeating itself. "It should be a very sobering fact that after we have lost previously we have gone a very long way to writing ourselves out of the script for very long periods." No one should underestimate what the Conservatives are willing to do to hang on to power. "It is hard to buck the historical trend that when the Labour Party loses, it loses for a long time."
After a "whirligig of activity" from ministers in the final months of the Brown regime – a symptom of an "obsession" with simply clinging to power – Mr Miliband is anxious to stress his desire to lead a grass-roots revolution in the Labour Party.
"It's a movement that understands that politics in the 21st century is about action, not just press releases. It is about the social, economic and cultural change that you build in the country and how you mobilise people behind that."
Amid much talk of retreating to political comfort zones and rival ideologies, the long leadership contest has appeared to ignore the fact that whoever wins on 25 September has a much bigger battle on his or her hands – winning a general election. As Mr Miliband now seeks to present himself as the "unity candidate", the breadth of support from both the left and right of the party would appear to stem more from a belief in his ability to win votes than to recall historical footnotes.
"We are a political party, not a debating society. We exist in a very imperfect political world to gain political power in the service of our values. It is a serious situation. We know the price of losing power – not for us but for the people we serve. When we lose, they lose."
It had been assumed the new coalition would shift to the centre ground to appease the Lib Dems, but Mr Miliband is scathing about what Nick Clegg secured for his party in the negotiations. "He got an AV pledge in a poison-pilled Bill. I don't see what else he got."
It could all spell disaster for the junior partner. "If you go to tea with the alligator, you get eaten. The Lib Dems have gone to tea with the alligator and history shows that the Tories will come out as a bigger, fatter alligator." The Conservatives "shoehorned a set of policies into a bit of political positioning" but failed to persuade voters to give them an outright majority. "People are quite angry. They felt the Labour government left them but they didn't think anyone came to meet them. No one won the election but we lost." Labour cannot afford to "ignore" the Tories and concentrate all the fire power on the Lib Dems.
"We have got to be trenchant in our criticism of the fact that 56 Lib Dem MPs are making possible shock therapy for our economy and our health service, but we have also got to be very, very respectful of millions of Lib Dem voters who chose to vote against us." He believes it is "more likely than not" that the coalition will go the full five years, and Labour must attack it on issues of "fairness, wealth-creation and from a communitarian perspective".
During the course of an hour, the only time he becomes downbeat is when he is asked about how the contest is affecting his family – and his relationship with brother, and rival, Ed. Stories persist about Mother Miliband's disapproval of her boys tearing chunks out of each other, albeit in attacks inevitably described as "thinly veiled" and "coded".
"My mum just is completely devoted to her kids and her grandchildren and nothing is going to come in between that. Part of politics is about protecting the people you love and that's your family. We are not a big family and that's why I think it's such a strong bond that we have got."
With ballot papers dropping through letter boxes from this week and the race still too close to call, many in Westminster expect the competition to turn nasty. Mr Miliband thinks not, insisting he and the four other contenders have "been going through this long process in a warm and comradely way". He admits that this has made it "boring", but avoided the "civil wars" of Labour's history. He has had a "very refreshing" time getting out of Westminster, meeting people, discussing issues including immigration, housing and crime that Labour too often overlooked.
"I believe the party wants us to be more proud of the good things that we achieved. People say to me 'is New Labour dead?'. New Labour is alive in SureStart centres, in neighbourhood policing teams, in gay rights, in the Human Rights Act. Those are all living memorials; those are the good things and we learn from them and we build on them."
The party must also learn from "the things we did wrong", including the 10p tax fiasco which "cost us more votes and more credibility than many other things". Except, of course, Iraq which at the 2005 election was "obviously a very big thing".
"Whatever position you took on Iraq, it's a fact that there was a terrible toll of lives and a terrible toll in trust. The party wants to move on. Political parties need to make themselves relevant agents of change in the modern world; otherwise the modern world takes a pretty dim view of them."
Except the issue of Iraq has repeatedly emerged as the focus of tensions between the Miliband brothers. David has staunchly defended the 2003 invasion, while Ed has revealed that he privately opposed it, and wanted the UN weapons inspectors to be given more time. Most people would assume the two Milibands spoke about this key issue, which dominated conversations at breakfast tables and bars across the country. David is, well, not too sure and launches into a discussion about the keeping of diaries and the nature of memory.
"I'm not going to go through any of the private conversations that we have as brothers, or as politicians, not least because I don't keep a diary. And I'm not going to start doing selective memory quotations, not least because I can't prove what was around at the time." Some might see this as a swipe at Lord Mandelson's recent memoirs, written in some instances several years after the event.
"The truth is you have a whole melange of different memories of what is going on at different times. If you don't keep a diary you rely on your memory, and even if I did remember with the exactitude of a diary, I wouldn't tell you. But since I don't, it's better not to."
However, having the conviction to stand by your past decisions and to say publicly what you believe is key to strong leadership. "One of the things about the modern world is... it's harder than it used to be to have things that are private and things that are public. And that's why consistency between the private and the public is very important." Take note, Ed.
The gentle swipes come thick and fast. Ed has suggested he could not work with Mr Clegg in the event of another hung parliament at the next election. David retorts: "We haven't got a leader of the Labour Party at the moment, so I am hardly going to start choosing leaders of other parties. It is up to the Lib Dems who their leader is."
The younger Miliband last week fired an Exocet at his brother's record as Foreign Secretary when he claimed he was "campaigning to make that change: for a foreign policy based on our values". David is unfazed, insisting he wants the same thing. "The alternative to an ethical foreign policy is an unethical foreign policy, and I don't believe in an unethical foreign policy.
"When the Foreign Minister of Iran says he wants to smack me round the chops – quote unquote – because I keep on going on and on about human rights in Iran, that is me doing my job as a Labour Foreign Secretary." He also recalls relatives of Sri Lankan refugees "coming up to me in the street" to thank him for his work on behalf of the Tamils. He stands by all his decisions in his three years at the Foreign Office. "There are two great responsibilities for anyone who holds high office: to defend the security of the nation and to uphold the values of the nation. Sometimes you have to think very, very carefully about how you meet those two goals, and they are very difficult decisions."
One of his predecessors at the FCO, Robin Cook, identified how New Labour's obsession with stamping out the public divisions of the 1980s created an atmosphere of dictatorship without a phase of debate and dialogue. Mr Miliband believes control freakery at the centre helped sow "some of the seeds of our downfall" in the election. "Party renewal stopped on 2 May 1997. Sadly, I think Tony in his own way did love the Labour Party but too often he defined himself against it." He wants more grass-roots involvement – the leaders of Labour in local government attending shadow cabinet, and the party chairman elected by members – and action to change the country, not just cling to power.
New Labour at its best combined the party's traditional values while making it electable. Mr Miliband believes the "breadth of support" that he has amassed – 1,000 local councillors, 101 MPs, 70 peers, 165 constituency parties – "speaks to important aspects of leadership".
"I am the unity candidate. I am the candidate who has shown how to build a coalition across the party and who has united different traditions." He believes his supporters, who range from left-wing Jon Cruddas to darling of the right Gerald Kaufman, think he can "reinvigorate Labour thinking and Labour organisation".
"The answer is to develop a modern Labour politics that really does take seriously what it says on our membership cards: power, wealth and opportunity in the hands of the many, not the few. That would be a transformation of our society."
It is Ed Balls who seems most adept at opposition politics, taking the fight in particular to the Education Secretary, Michael Gove. Is this the sort of bruiser who will be needed in a Miliband top team? It is no surprise in times of coalition politics that Mr Miliband comes over all Churchillian.
"We need all the talents. It's not fight them on the beaches, but we are going to have fight them out on the streets; we are going to have to fight it out in the boardrooms; we are going to have to fight it out in the House of Commons. We are going to have fight it out in local government chambers, in community halls, on the shop floor. And we are going to have to fight it out with ideas and with organisation.
"We are going to need every conceivable talent to win this thing because the people we are up against are well funded, clear in purpose and absolutely determined to keep us out for a generation."
For the full transcript go to: independent.co.uk/jrentoul