On Saturday I went to the Jeremy Corbyn rally in Milton Keynes. It was a great day. The sun was shining, people were in good spirits, and the event was ably chaired by Matt Wrack of the Fire Brigades Union. Speakers addressed the crowd from the top of the now iconic fire engine.

First up was Niamh Lavelle, a local first time voter who delivered a powerful speech. She began by describing the development of her political understanding. She explained how Jeremy’s campaign for leader last year struck a chord with her. For the first time she felt there was a politician who could relate to her life and her experiences. She gave a sobering account of her anxieties over an insecure and uncertain future: the fact that she was unlikely ever to own her own home, the result of the EU referendum, and the state of the NHS.

The NHS was a recurring theme of the day and was taken up by Danielle Tiplady, a student nurse who highlighted the consequences of the government’s abolition of the student nurses’ bursary. In future student nurses will have to fund their own training by taking out loans. Danielle also spoke of life on the front line for community nurses who get to see the human cost of the cuts in terms of the effect on patients.

Chris Webb gave a rousing speech which pointed out the historic nature of the campaign. In twenty years, he suggested, children are going to be learning about these events in school. When they ask us about our own personal roles, he asked, what will we tell them? Are we going to have to confess we did nothing, he challenged us, or will we be able to tell them with pride that we fought for a better world?

Diane Abbott was excellent as always. She expressed her pride in serving as Shadow Secretary of State for Health under Jeremy’s leadership and delivered an eloquent rebuttal to the arguments that immigrants are a drain on the NHS and drive down wages. She pointed out that immigrants played an important role in building the health service. Wages are driven down not by immigrants, but by predatory employers, insufficiently strong trade union organization, and globalization. She pledged to stand firm against creeping privatization of the NHS, for a moratorium on PFI, and for a renegotiation of PFI agreements which are a burden on the NHS. She and Jeremy will stand with nurses, doctors, and other staff because the NHS is only as good as the morale of those who work in it. If the Tories manage to break the junior doctors, they will move onto other groups of NHS workers. She also pointed out that mental health care has been neglected too long and committed to making sure it gets the priority and funding it deserves. She finished by describing the power of the forces ranged against us but pointed out we have strength in numbers and we can win.

The final speaker was Jeremy and he was inspirational. He thanked the FBU for providing the fire engine and paid tribute to all the emergency services for the work they do. His speech was a tour de force pointing out not only how far we have come since Labour was abstaining on the Welfare Bill a year ago, but also how much still needs to be done. He touched on many issues from the NHS, mental health, education, tax avoidance and evasion, the EU referendum, economic and industrial strategy, inequality, homelessness, zero-hour contracts and employment, community and solidarity, education, culture, climate change, human rights, racism and xenophobia.

Jeremy made a lot of points but two struck me in particular. Firstly, as is often pointed out, austerity is not an economic necessity but a political choice. However, because it has always been presented as the opposite – a necessity not a choice – the idea is deep-rooted. We have a big job of work to do to change people’s attitudes. Secondly, this campaign is not just about campaigning for the leadership of the Labour Party, but it is also about developing our campaigning ability. Once the leadership election ends with Corbyn landslide number two, we will need to take our ideas out in the country to ensure victory at the general election. The lessons we learn from our experience in this campaign will be invaluable.

It has been suggested that Saturday’s rally was the biggest political meeting Milton Keynes has ever seen. I don’t know if that’s true and I found it difficult to estimate the size from ground level – but it was in the thousands rather than hundreds. This is quite remarkable. Far from being a Labour heartland, Milton Keynes is a small town in the South East which voted Conservative in the last two elections. If people are turning up in such numbers even here, something significant is happening.