Ed Miliband vowed today to drive David Cameron out of power after just one term as he told the Labour Party he was "ready to lead".
In his crucial first leader's speech at Labour's annual conference in Manchester, Mr Miliband said he represented a "new generation" which would deliver change to the party and the country, with "different attitudes, different ideas, different ways of doing politics".
He attempted to draw a line under 13 years of Labour government, admitting the party in power had been wrong to claim it had ended boom and bust, to encourage a culture of debt, to fail to regulate the City and to ignore concerns about immigration, and wrong to go to war in Iraq.
Labour must now address voters from a position of "humility", he said.
Under his leadership, he said that Labour would be a party of "optimists" with a new vision of the good society.
In a jibe at Mr Cameron - echoing the Prime Minister's own comment to Tony Blair that "you were the future once" - Mr Miliband said: "You were the optimist once but now all you offer is a miserable, pessimistic view of what we can achieve. And you hide behind the deficit to justify it."
Mr Miliband insisted that he was "serious about reducing our deficit" and would be "responsible in opposition" and not attack everything that the coalition Government does.
But he hinted that he might move away from former chancellor Alistair Darling's plan to halve the deficit in four years, describing it as "a starting point" and insisting that the Government was "irresponsible" to leave the country without a plan for growth to operate alongside its paying-down of national debts.
Getting the coalition out of power after just one term would be "the purpose of my leadership of this party", said Mr Miliband.
Paying tribute to the achievements of Tony Blair and Gordon Brown in government, he said New Labour had gone from being "reforming, restless and radical" to becoming the voice of the establishment, "the prisoner of its own certainties".
And he said: "I stand before you, clear in my task: to make Labour a force that takes on established thinking, doesn't succumb to it, speaks for the majority and shapes the centre ground of politics."
In his most personal speech yet, Mr Miliband described how the experience of his parents as Jewish refugees fleeing the Nazis in wartime Europe had shaped his values.
His parents arrived in Britain with nothing and "this country gave them everything", he said.
They provided him and elder brother David, whom he beat in the Labour leadership race on Saturday, with "the things I want for every child in this country - a secure and loving home, encouragement and the aspiration to succeed", he said.
And they instilled the two brothers with a sense of "responsibility to leave our world a better place and never walk by on the other side of injustice".
He promised: "My beliefs will run through everything I do. My beliefs, my values are my anchor and when people try to drag me - as I know they will - it is to that sense of right and wrong, that sense of who I am and what I believe to which I will always hold."
Mr Miliband praised his brother as an "extraordinary" person but made no direct reference in his 56-minute speech to his defeat of David in the leadership race or to the speculation which has overshadowed the Manchester conference about whether he will walk away from politics or seek a chance to serve in the shadow cabinet.
Mr Miliband brushed off descriptions of him as "Red Ed", comparing them to cartoonists' depictions of him as Wallace from Wallace and Gromit or Forrest Gump, and saying: "Come off it. Let's start to have a grown-up debate in this country about who we are, what we believe and what kind of country we want to build."
He attempted to prove that he would not be the creature of the unions whose votes propelled him to the leadership.
While supporting "responsible trade unions", he would have "no truck... with overblown rhetoric about waves of irresponsible strikes".
On the key issue of the economy, he questioned Mr Cameron's "patriotism" by suggesting that his drive to eliminate the structural deficit within one parliament risked damaging the country in which this generation of children will grow up.
"I am serious about reducing our deficit," he said. "But I am also serious about doing it in a way that learns the basic lessons of economics, fairness and history."
Labour was to blame for "not building a more resilient economy" ahead of the 2008 financial crisis, he admitted.
But he added: "What we should not do as a country is make a bad situation worse by embarking on deficit reduction at a pace and in a way that endangers our recovery.
"The starting point for a responsible plan is to halve the deficit over four years, but growth is our priority and we must remain vigilant against a downturn."
Warning of the danger that austerity measures will slow down the economy as well as damaging public services, he said: "When you reduce your economic policy simply to deficit reduction alone, you leave Britain without a plan for growth.
"It's not responsible, it's irresponsible and we should say so.
"No plan for growth means no credible plan for deficit reduction."
And in a direct message to the Prime Minister, he said: "True patriotism is about reducing the debt burden we pass on to our kids.
"But Mr Cameron, true patriotism is also about building an economy and a society fit for our kids to work and live in."
In a speech which was light on policy commitments, Mr Miliband indicated his backing for a banking levy, a living wage, benefit reform, an elected House of Lords, and action to support the family - particularly in terms of ensuring time to spend with children.
He said he would back House of Commons reform and vote Yes in the referendum on the Alternative Vote.
And he promised that Labour would be "on the side of communities" trying to save local post offices, shops and pubs.
Under New Labour, the party became "naive" about the benefits of the market economy, he said.
And he added: "We must never again give the impression that we know the price of everything and the value of nothing."
He called on Labour to "reclaim the tradition" of civil liberties from Tories and Liberal Democrats, acknowledging that Tony Blair's attempt to secure a 90-day detention period for terror suspects had undermined the government's other counter-terror measures.
And on the Iraq War - launched before he entered Parliament in 2005 - Mr Miliband gave the strongest admission yet by a senior Labour politician that Mr Blair should not have taken Britain into war alongside the US.
"I do believe that we were wrong," he said. "Wrong to take Britain to war, and we need to be honest about that."
In an apparent signal that he would not bind himself as closely as Mr Blair did to Washington, Mr Miliband said that Britain's alliance with the US was "incredibly important to us", but added: "We must always remember that our values must shape the alliances that we form and any military action that we take."
On Afghanistan, he pledged to work in a bi-partisan way with the Government "to support our mission and ensure Afghanistan is not a war without end".
In a section of his speech trailed last night, Mr Miliband distanced himself from the Blair/Brown era of New Labour, saying: "It was courage that made us such a successful political force.
"But our journey must also understand where it went wrong.
"I believe that Britain is fairer and stronger than it was 13 years ago. But we have to ask, how did a party with such achievements to its name end up losing five million votes between 1997 and 2010?
"The hard truth for everybody in this hall is that a party that started out by taking on old thinking became the prisoner of its own certainties."
He added: "Let me say to the country: You saw the worst financial crisis in a generation, and I understand your anger that Labour hadn't changed the old ways in the City which said deregulation was the answer.
"You wanted your concerns about the impact of immigration on communities to be heard and I understand your frustration that we didn't seem to be on your side.
"And when you wanted to make it possible for your kids to get on in life, I understand why you felt that we were stuck in old thinking about higher and higher levels of personal debt, including from tuition fees.
"You saw jobs disappear and economic security undermined, I understand your anger at a Labour government that claimed it could end boom and bust."
The most important task of the new generation now leading Labour would be to "win back the trust of the country".
Trying to shake off suggestions that he would take Labour to the left, Mr Miliband insisted he would "always stand up for the mainstream majority... fight for the centre ground, not allow it to be dominated or defined by our opponents".
He said: "This generation wants to change our economy so that it works better for working people and doesn't just serve the needs of the few at the top.
"This generation wants to change our society so that it values community and family, not just work, because we understand there is more to life than the bottom line.
"This generation wants to change the way government works because it understands the power of the state to change lives but also how frustrating it can be if not reformed.
"This generation wants to change our foreign policy so that it's always based on values, not just alliances.
"And this generation knows very profoundly that to change Britain we need a new politics. Above all, I lead a new generation not bound by the fear or the ghosts of the past."
He concluded his speech to a standing ovation with an appeal to activists' sense of optimism.
"We are the optimists in politics today," he said.
"So let's be humble about our past. Let's understand the need to change. Let's inspire people with our vision of the good society.
"Let the message go out, a new generation has taken charge of Labour. Optimistic about our country. Optimistic about our world. Optimistic about the power of politics.
"We are the optimists and together we will change Britain."Reuse content