Labour leader Ed Miliband invokes the spirit of wartime Britain to argue that political leaders have a responsibility to ensure that “we leave our country a better place than we found it”.
Mr Miliband used a concept associated with the left of the Conservative Party and invented by Benjamin Disraeli – one nation – to paint a picture of Britain at the crossroads of economic recovery or stagnation.
Speaking without notes, he told delegates at the Labour conference: “We won the war because we joined together as one nation. We built the peace because governments, Labour and Conservative, understood that we needed to be one nation.
“Every time Britain has faced its gravest challenges, we have only come through the storm because we were one nation.”
Mr Miliband sought to deny David Cameron the right to describe himself as a “one nation” Conservative by saying: “You can’t be a one nation prime minister if you raise taxes on ordinary families and cut taxes for millionaires.”
Although the Labour leader criticised the coalition government’s handling of the economy and its deficit reduction programme, he said his party had to be responsible with the public finances.
“One nation is not a way of avoiding the difficult decisions. It is a way of making them. To be one nation, we have to live within our means.
“Because borrowing is getting worse not better, there will be many cuts made by this government that we won’t be able to reverse, even when we would like to do so.”
I would not be standing here today as leader of the Labour Party without my comprehensive school education. Ed Miliband
Returning to his theme of the “British promise”, Mr Miliband said he had a “duty to leave our country a better place than I found it”, adding: “I believe we should never just shrug our shoulders at injustice, and say that’s the way the world is.”
He talked about his own upbringing, as a comprehensive school boy and son of Jewish immigrants who fled the Nazis.
He told delegates in Manchester: “I went to my local school with people from all backgrounds. My school taught us a lot more than just how to pass exams – it taught people how to get on with each other, whoever they are and wherever they were from.
“I will always be grateful because I know I would not be standing here today as leader of the Labour Party without my comprehensive school education.”
Mr Miliband said he understood why Labour had lost the last election and voters had turned to the Conservatives. “You were willing to give them the benefit of the doubt, but we’ve had long enough to make a judgement. They promised change, but things have got worse not better.”
He criticised the government’s unwillingness to change course on the economy. “So when David Cameron says lets just stick to the same plan, it will be good for us in the end. Don’t believe him.
“Just like if the medicines not working you don’t just keep taking it. You change the medicine, and you know what else you change? You change the doctor.”
Mr Miliband said there could be no return to old Labour, adding: “We must be the party of the private sector just as much as the party of the public sector, as much the party of the small business struggling against the odds as the home help struggling against the cuts.”
Labour needed to be the party of the south as well as the north, the “squeezed middle” and “those in poverty”.
The Labour leader outlined plans for a major shake-up of vocational education to benefit the “forgotten 50 per cent” neglected by successive governments.
His plans would see a new technical baccalaureate awarded at 18 to youngsters who complete a programme of work experience, school-based vocational training and academic courses in English and maths.
At the same time, employers would be given control of a £1bn annual budget for apprenticeships, allowing them to shape the training they need to run their businesses effectively.
In using the words “one nation”, Mr Miliband was borrowing a phrase from Disraeli’s 1845 novel Sybil that has come to be associated with reducing the gap between rich and poor and tackling social problems.
It described the rich and poor as “two nations between whom there is no intercourse and no sympathy; who are ignorant of each other’s habits, thoughts and feelings, as if they were dwellers in different zones or inhabitants of different planets; who are formed by different breeding, are fed by different food, are ordered by different manners, and are not governed by the same laws”.
In 1872 Disraeli, as Tory leader, spoke passionately about the need for the state to intervene to help the poor in an address at Manchester’s Free Trade Hall, which stood around 100 yards from the stage where Mr Miliband was speaking.
It fell out of favour under Margaret Thatcher, but was also used by former Labour leader Tony Blair.
Dame Tessa Jowell, who left the shadow cabinet following the successful Olympics, told Channel 4 News: "I thought it was an absolutely extraordinary speech, the best leader's speech for many many years. I think the public will have liked what they heard."
Deputy leader Harriet Harman said: "It was a real tour de force. He broke through and showed not just everybody in here, but the whole country, what he's made of - real leadership qualities."
Len McCluskey, general secretary of the Unite union, has clashed with the Labour leader over public sector pay restraint, but said of Mr Miliband's speech: "I thought, if that's not the a prime minister in waiting, then I don't know what is."
But Conservative Party chairman Grant Shapps said: "To prove he is credible, Ed Miliband had to do more than give a speech to rouse the Labour Party faithful; he had to show that he had learned from the mistakes that Labour made in office.
"Instead he failed to back our welfare cap, failed to back our immigration cap and still stands for more spending, more borrowing and more debt - exactly what got us into this mess in the first place. Sadly, Labour isnâ??t learning."
The Liberal Democrats said Mr Miliband's decision to use the phrase "one nation" in his speech followed leader Nick Clegg's adoption of the expression in his spring conference speech six months ago.