Looking back on my three years as chair of Progress, it’s difficult to believe how much has happened. In 2002, the Labour government was a year into its second term. Two issues stood out as the poles around which the next few years would be defined: the need for ‘delivery’ in public services to satisfy the expectations of a public impatient for change; and the repercussions of 9/11 and the US-led ‘war on terror’.

With hindsight, I’m not sure anyone realised what kind of imprint either would leave. On the international stage, the war in Iraq polarised many in our party, and in the country as a whole. Controversy about the justification for war engulfed public debate, damaging public trust and depriving other issues of the attention they deserved. But, on the positive side, a politics that had seemed moribund when turnout slumped to its lowest level in modern times now showed new signs of life.

Domestically, huge flows of investment in public services finally began to come on stream, delivering real, immediate benefits in falling waits for NHS treatment, rebuilt and refurbished school buildings and Sure Start for parents in disadvantaged neighbourhoods. But ministers began to realise that the language of delivery was insufficient: the expectations of citizens had already moved on, towards a claim for more choice and voice in how services are provided.

The Labour party meets in Brighton less than a year into a historic third term that already promises to be the most challenging and exciting period of Labour’s time in office. The London bombings have brought terrorism back to centre stage, bringing into sharp relief debates about balancing security with civil liberties and preserving the human rights of minorities without jeopardising the safety of the British public as a whole. The referendums in France and Holland have reopened the argument about the core purpose and direction of the European Union. Make Poverty History has tapped into the latent idealism and activism of a whole generation, and started to draw them into formal politics in a way that parties themselves have found difficult. Winning the right to stage the Olympics presents a unique opportunity to marry practical economic and social change with a national cultural investment. All of these issues make the case for innovative, challenging thinking more pressing.

Throughout my time in office, I tried to ensure that Progress was a vehicle for mobilising discussion and debate from all sides of our diverse and vibrant movement. Through its magazine and latterly its journal, and through its seminars, conferences and events, Progress has offered a space for dialogue at once open and inspiring. I will remember especially its annual rally on the Sunday night of Labour party conference week as a particularly energising experience that always set me up for a good conference. That task was important in the last three years; it will be crucial in the next three.

If we can continue to play that role successfully, we can start to build towards a general election at the end of this decade at which the unimaginable prize of a fourth successive victory, and with it the embedding of what Gordon Brown has called the ‘progressive consensus’, could lie within our grasp. If we cannot, then a Conservative party finally showing signs of regrouping after a decade of disarray could yet thwart our ambitions.

With that task in mind, I’m delighted that Stephen Twigg will be replacing me as chair. Stephen is a great communicator with a fine political mind, just the assets Progress needs as it looks to develop over the coming years. And I look forward to having a continuing input into that development in my new role as a patron of the organisation.

‘May you live in interesting times,’ runs the old Chinese curse, and the last few years have certainly been that. I don’t see it as curse, however. It is at times like this, when a particular issue can divide a whole family, that passionate argument about the big issues of our time is most necessary, provided there are organisations that exist to channel and influence that argument in constructive ways. That’s why Progress is so important. We know that people are turned off by ‘yah-boo’, adversarial politics. But we should never interpret that criticism of a particular style of debate as a sign of people losing their appetite for debate itself. Healthy debate is the lifeblood of politics.

These have been fascinating times to be in politics, and to be in the Labour party. To have viewed them through the particular lens that the office of Progress chair affords has been a special privilege. David Lammy was chair of Progress 2002-2005