Last week’s Labour party conference was a highly emotional event. The announcement of Ed’s election as leader of the party was greeted – both by delegates and by the new leader himself – with a somewhat stunned response. Many people seemed initially bemused, and those who’d been supporting David naturally felt particularly acute regret. But a strong sense of unity and purpose became increasingly notable as conference wore on. All week, the debates in the hall reflected a spirit of consensus, and a determination to go on the attack against the government, fringes were well attended and thought provoking, the mood in the bars and coffee lounges vibrant and upbeat. It hasn’t always been like that.

So I think we stand in a good place now as a party, and that Ed will take us from strength to strength. And I say that not just from wishful thinking, from a rosy and idealised post-conference glow, but for two particular reasons, which were echoed in Ed’s Tuesday speech.

The first is about the mood of the conference, the determined, outward-looking passion that characterised the week. That came from those attending, members, trade unionists, and senior party figures, sharing a common goal. Undoubtedly, the many new and younger members attending conference for the first time contributed to that. Those new members are a source of significant strength for us, and we must make sure we capitalise on the influx of enthusiasm and dynamism that they bring.

Something important is happening here, and it’s something we shouldn’t underestimate or ignore. For many years, I also attended Tory conferences, and I’ve learnt an important lesson from comparing the two parties at our respective meets over the past couple of decades. In the mid-1990s, and through the early years of the New Labour government, our conference was characterised by the increasing number of young delegates attending, who each year gave the conference – and the party – a vibrant, forward-looking feel. Of course some were there from naiveté, personal ambition, opportunism – but they also created an energy, a confidence and an imagination that drove on our radicalism, enhanced our connectedness to the mood of the country, and helped bring electoral success. Then, two or three years ago, I noticed something alarming: it was the Tories who were attracting those ambitious younger members, while our party was ageing and static. Suddenly, Cameron’s Conservatives looked the exciting place to be.

This year that has changed again. Our conference felt reinvigorated, with new and younger members once more evident. So when Ed spoke about a new generation he was right – 45,000 new members, many young, from diverse backgrounds, 40 per cent of them women, are rejuvenating and revitalising our party now.

I don’t say this to imply that only younger members have anything worthwhile to offer, but I do say that a party that has no appeal for young people is a party than cannot survive – and that was where we were heading in the past few years. Now we are attracting a new generation – and we need them at the heart of our party as we build a progressive vision of the future to meet the demands of a more challenging age.

The second reason I feel positive comes from the policy content of Ed’s leader’s speech. During the leadership campaign, the press sought to portray Ed and David as two extremes: one a Bennite, one a Blairite – a ludicrous and exaggerated picture of two leadership candidates with far more uniting than dividing them. But there were of course degrees of difference, and Ed, with his position on a range of policies, from the living wage through tuition fees to the war in Iraq, has overtly and expressly positioned himself and the party on the centre left.

Many in and outside the party are convinced that’s a position from which we cannot win. I don’t agree – and again that’s not wishful thinking, I say it based on experience.

In the general election, in my constituency we achieved a tremendous result: an increased majority, and a swing away from Labour of well below 1 per cent. We did that by campaigning with the messages of the progressive left. I wasn’t afraid to tell voters that I was proud of our record on redistribution and wanted to do more, I was unashamed about our investment in education, health and early years, and unapologetic that a progressive taxation system was needed to pay for it, I told voters explicitly that while I knew no-one in the Labour party had made the decision to go to war lightly, personally I didn’t support our joining the war in Iraq. None of that appeared to frighten the voters of Stretford and Urmston – on the contrary, repeated with conviction and commitment (and backed up with good organisation and a great campaign team), it proved to be a winning formula.

Of course I accept that the north is different from the south of England, but it’s important that we understand what drives that difference, and how that means we should respond. High living costs, especially housing costs, and access to high quality public services (particularly choice of school) create specific pressures in the south. So our policy answers must be designed to address those concerns, our progressive agenda and narrative must speak to everyone – from the middle Britain families in the south, to those living in workless communities in the former industrial heartlands of the north.

That doesn’t mean we carry on with the trimming and the tacking that characterised our recent approach to difficult policy choices. Instead we can learn from the success of the new Labour government in 1997 in marrying popular and pragmatic policymaking with clear progressive principles. From the establishment of an ethical foreign policy to the introduction of a minimum wage, from the Human Rights Act to the New Deal, Labour’s policy programme in the 1990s demonstrated that progressive policy measures can simultaneously be economically sensible, widely popular, and socially just. A radical policy programme, founded on equality, universalism, and responsibilities coupled with rights, swept Tony Blair to power in 1997. It can surely do so again.

What’s needed now is a space for thinking, for defining the progressive policies that address the structural drivers of disadvantage right across the country, that will rebuild and grow our economy, and resonate for all members of our society – and we must include all in our party in that process and debate. Caution and an over-centralising control-culture led us to miss the opportunity in the aftermath of the banking crisis to redefine our vision based on greater equality and an end to the excessive reward culture that nearly destroyed our economy, and to respond to the yearning of the electorate for a different kind of society – we lost an election as a result. Now with a new leader, a dynamic and determined party, and a government whose cuts programme is already alarming the voters, we can and we should be ambitious, radical, progressive and bold. The party is ready for it and the country will need it. It’s a platform from which we can win.