Ed Miliband has said Labour will offer hope in 2013, to a Britain let down by the coalition government.
In his New Year speech on Friday, Miliband acknowledged that there were "no easy answers" to the country's problems, but insisted: "I do believe that Britain can be better than it is. There can be hope for people again."
He promised to flesh out his One Nation Labour slogan in the new year with concrete policies on business, education and welfare.
Labour's approach will be based on the principle that "we cannot write anybody off in our country", and will challenge the idea that wealth "trickles down" from those at the top of the economy, he said.
Instead, policies should aim to reward "the forgotten wealth-creators of our country", such as people doing two jobs to make ends meet, small businesses struggling against the odds and young people seeking qualifications and work.
But he also warned that a One Nation society will require "responsibility" at every level of society, from corporations paying their fair share of tax to Government helping ensure jobs are available and those who are able to work taking on employment when it is offered.
In a notably positive message, Miliband said that Britain must harness the Olympic spirit of 2012 as it faces the future. And he hailed the "indomitable spirit" of people trying to find work in the current difficult economic conditions, including a man he met at a food bank who had walked 11 miles to a job interview because he could not afford the bus ticket.
In what is likely to be seen as a swipe at David Cameron, the Labour leader said: "We've all at least got to imagine walking in the shoes of others, to be the man who walked 11 miles to the job interview. That's what it means to be a One Nation Prime Minister."
Miliband sought to use the video address to draw a contrast between a "government of broken promises and broken dreams" and a Labour opposition offering hope for the future.
"I don't offer easy answers and I'm not going to offer false promises either. But I do believe Britain can be better than it is. There can be hope for people again," he said.
"This Government is a government of broken promises and broken dreams.
"They want you to believe that we have a good government being let down by bad people. We don't. We got a bad government that is letting down the good people of this country.
"Just think about the spirit of the Olympic Games that we saw in 2012. That's what we've got to harness for the good of each and the good of all. That is what One Nation Labour is about and if we work together we can create One Nation Britain."
Without giving any details about new policy proposals, Miliband said he aimed to "tip the scales towards hope" and ensure that Britain uses the talents of all of its people.
And he promised that Labour would "reach out to every part of Britain" and be the party of the private sector as well as the public and the South as well as the North.
"We cannot write anybody off in our country," he said. "That is what One Nation is all about. And that is what you will be hearing about from the Labour Party in 2013.
"How you create a One Nation economy, not based on the old idea that wealth trickles down from those at the top to everyone else, but that we need to reward the forgotten wealth-creators of our country.
"The people doing two jobs, the people coming home after our curtains are closed at night and going back out to work again the next morning before our curtains are open.
"The small businesses struggling against the odds, we need to help them succeed.
"And we need to help our young people too, including the forgotten 50% who don't go to university who want a qualification, an apprenticeship and a job.
"We need to help our small businesses so they don't find they're serving the banks rather than the banks serving them. And we need to change the rules of the game for business, so that we have rules that encourage long-term wealth creation which is what our country needs.
"In a world where there is less money around, that for the Labour Party is the route to a fairer society. A country where people look at the way our country is run and say `Yes it is run according to my values, everybody showing responsibility, from corporations paying their fair share of tax, to people who can work doing so'."