By Brian Wheeler
Political reporter, BBC News
On the face of it, Ed Miliband has an impossible task.
Ed Miliband says the key to the manifesto is optimism
Depending on which of his Cabinet colleagues you listen to, Labour has either "lost the will to live", is heading for a "really bad defeat" or, as his older brother David has it, needs to "show we stand for the future".
As the party gathers in Brighton for its final conference before a general election, many pundits are already writing New Labour's obituary.
Ed Miliband's job, as the party's manifesto co-ordinator, is to convince voters that the opposite is true: That far from a being party exhausted by 12 years in power, Labour is bursting with new ideas - and that it deserves an unprecedented fourth term to put them into action.
If the 38-year-old energy and climate change secretary is weighed down by the scale of this task, he does not let it show.
Tieless, in a crisp white shirt, he confidently bats away predictions of imminent doom for Labour, when we meet in his large, airy office at the newly-refurbished department of energy and climate change building just off Whitehall.
And he sets out in meticulous detail the steps he says the party will take to win the next election.
2005: Britain Forward, Not Back
2001: Ambitions for Britain
1997: New Labour: Because Britain Deserves Better
1992: It's Time to Get Britain Working Again
1987: Britain Will Win with Labour
1983: The New Hope for Britain
1979: The Labour Way is the Better Way
"I have no question that, historically speaking, fourth terms are tough to win and we've gone through a difficult economic situation," he admits.
"But I am very clear - and I think this does contrast with the other parties - we have a clear analysis which will underlie our manifesto.
"If you think about politics in the next five years it will be characterised by the response to three different crises: the economic crisis, which we are starting to come out of; the political crisis caused by expenses; and - in my view - the climate crisis.
"And the very clear message from our manifesto will be - you can't go back to business as usual on any of those. We need a different sort of economy, going forward, we need a different sort of politics going forward."
He has little time for claims that the government is running out of ideas, saying: "I think that cliche couldn't be further from the truth as far this government is concerned."
Whether it's on social care, schools policy, climate change or Transport Secretary Andrew Adonis's proposals for a high speed rail network, "this is a government firing on all cylinders," he insists.
But he does agree that if Labour is going to stand a chance of averting defeat, the party's manifesto is going to have to be a far more bold and "radical" than it was in the programme presented to voters at the previous two general elections.
Mr Miliband adds: "Half way house solutions and safety first solutions aren't the answer, we are very conscious of that.
"I think you will be seeing some of that at our conference and you will be seeing it in the manifesto document itself".
The really big decisions on tax and spending will come in November's pre-Budget report and Mr Miliband is reluctant to venture into these policy areas, saying only that there will be "a very big difference" in priorities between Labour and the Tories.
But with some at the conference expected to call for a cut to child benefit to better off families, Mr Miliband goes slightly further on the issue of universal benefits, saying it is "important" to have a mix of universal and targeted welfare.
"Lots of families need the support that child benefit provides, not just the poorest," he says.
The main thrust of Labour's next manifesto will be to contrast Labour "optimism" with Tory "pessimism," he argues.
Does that mean the party is ready to embrace some of the policies it had previously rejected as too "radical" for Middle England?
Mr Miliband denies this, saying the premise behind the question is "incorrect", and adds it is possible to be both "bold and New Labour."
He expands on the theme: "All parts of society want an economy that is rebuilt on different foundations around a broader industrial base, around less inequality, for example.
"People want big political reform and I think that's important. People want a big response to climate change.
"People want issues like social care and time with their families to be addressed.
"I don't accept this sort of distinction between a core vote or a swing vote."
In 1983, the last time Labour was as far behind in the polls as it is now, Labour's manifesto writing process was annexed by the left of the party.
They believed the party was already destined for defeat and therefore drew up the most overtly socialist manifesto the party had ever produced.
It was dubbed the "longest suicide note in history" by critics.
"We're hoping to avoid that," smiles Mr Miliband, who has been tipped in some circles as future Labour leader.
But will Gordon Brown's hands be tied when it comes to the policies he presents to voters?
Unison, one of the party's biggest trade union funders, have already threatened to withdraw support for the manifesto unless Labour promises not to cut public sector jobs.
Says Mr Miliband: "Of course the trade unions have a voice in our party. Everybody knows that.
"But I don't see any difference now as compared to before and actually the best ideas often come from party members."
Labour is a lot more dependent on union funding than it was in the Blair era - and it is they who will be writing the cheques during the campaign, I suggest.
"The decisions trade unions make about who to support financially at the election are one thing. The decision about what goes in our manifesto is another.
"But the most important voice as far as I am concerned to listen to, as far as the manifesto is concerned, is party members and party members in their role as representing the people of Britain."
He adds: "Those are the voices I am listening to. Some of those chime with the voices of the trade union movement, some of them don't."
He says the party is going to make good on Gordon Brown's promise when he took over as leader that the whole party would be balloted on the manifesto - just like Tony Blair did before the 1997 election.
But Mr Miliband may find by the end of the week in Brighton that this may not be enough to mollify the unions, some of whom believe the only way to win the election is to bury New Labour once and for all.