John Denham and Peter Hain write:
Three years ago few gave Labour much chance of winning the 2015 general election. Crushed in 2010 and widely if unfairly blamed for the economic crisis, history also told us that no party had ever come back from such a position to win a majority in just one term. These were the unpromising circumstances in which Ed Miliband became leader.
Although we had been in power for 13 years Ed was not afraid of criticising our record. He had been a cabinet minister, as we had been, and like us, he was proud of the great bulk of our achievements. But he was also clear that many of the problems facing Britain required fundamentally different approaches and new solutions.
At the heart of his argument was the idea that the British economic model that had evolved over nearly 30 years was not capable of enabling this country to pay its way, or of offering jobs which would let our citizens enjoy a good, secure standard of living.
The banking crisis was global, and Labour had responded well, showing global leadership and decisive action at home. But it also revealed an economy that was too dependent on the riskier parts of the financial services industry and with too little depth everywhere else.
Ed's willingness to confront these uncomfortable truths helped firm up our core vote, win back some of those who left us in 2005 and 2010, and establish a lead over the Tories. His attempts to define the challenges struck a chord with the public.
He was the first to point out that our economy failed the "squeezed middle" as well as the poorest. He knew that low incomes could not be alleviated by redistributive taxation alone. He was brave enough to confront media power and to lead criticism of the banks.
His understanding that these structural problems reflected wider dysfunctions and injustices about economic and social power led him to launch the debate about "responsible capitalism".
There was initially much media sniping, but then his critics had to concede that he was right: the "rules of the game" had to be changed and financial regulation radically improved, both to discourage destructive corporate behaviour and encourage companies committed to long-term investment, innovation and good employment practice.
This was never a "leftwing" agenda in an "old Labour" sense. It was clear to a broad spectrum of opinion that both the current government's and New Labour's over-reliance on free market liberalism and underplaying the role of the state in modern economies lay behind Britain's economic weakness.
At the heart of Ed's One Nation vision was his willingness to take a different direction on economic policy. It gave us credible answers to the problems facing the squeezed middle and to the question of where decent jobs would come from.
It's no coincidence that when these messages were at their sharpest and most consistent, Labour's lead was strongest. It's in the past few months, when we've heard less of this fundamental approach to the economy, that Labour's lead has weakened.
On the one hand, the commonsense acceptance that incoming Labour ministers will have to work to the first year budgets they inherit has been wrongly seen as wholesale acceptance of Osborne's disastrous economic strategy. On the other, criticism of poor corporate behaviour has been muted, and areas such as tax abuse have ceded to simplistic coalition sloganeering.
All the signs point to Ed Miliband being the next prime minister – and this because of, not despite, his leadership. But the modest Tory revival is a healthy warning to stick to his core message. Detailed policy can wait, but on the big issues it is not better to have less definition rather than more.
The public don't like any politicians much. They have little time for parties who just want to rubbish the other lot. For Labour, a party that was in power so recently and for so long, an acrimonious debate about whose record is worse is unlikely to produce a decisive winner.
The most valuable members of the shadow cabinet have been those who have set out radical long-term visions for their area of responsibility, such as Andy Burnham and Liz Kendall on the need to integrate a National Care Service into the NHS. Labour has been at its strongest when we have risen above the party political dogfight to speak the truth about what needs to be done.
There's nothing to worry about in our current position so long as the entire Labour leadership team swiftly rediscovers the ability to do the same.