Your question makes me sound very old! In fact I’ve been incredibly rejuvenated by the last couple of years. Undoubtedly this is, in my opinion, the high point of the Left in the Labour Party in the last seventy-five years. The program that was presented in the manifesto was clearly a transformative program of the Left, with bold, imaginative policies which had a lot of popular appeal, and everybody recognizes they were discussed much more widely than is the norm than is with election manifestos.

People who were unconnected to politics knew what was in it, and liked it. That was evident on the doorstep. It was presented as a left manifesto by us, but also by our opposition. Although some people argued in advance of the publication of the manifesto that policies don’t matter, in the end I think we showed that they do.

Maybe they didn’t always but that’s because in recent decades people have been presented with a smorgasbord of small ideas designed to appeal to some segment of society, and the overall package has simply been unexciting. When you operate through a process of triangulation, when you try to beat the Tories not on the basis of a broad offer but with technocratic tweaks here and there, people don’t respond. We made sure in this election that the parties didn’t look the same. I didn’t hear anybody say “You’re all the same!” during the campaign, which is what we’ve heard for the last twenty years.

Jeremy has been uncompromising in the way he’s presented himself, he hasn’t denied anything about his past. In fact, his popular appeal is based on his past. Once we got into the campaign and broadcasters were obliged by law to be balanced in their reporting, people saw Jeremy in an unfiltered fashion. It made a huge difference.

So much of Jeremy’s coverage over the last two years has been his opposition — both inside and outside the Labour Party — rubbishing him. Once that cycle was broken, and people got to see him and his ideas in the course of a campaign, it all changed. We went from 24 percent to 41 percent in a six-week period. No party has ever achieved that.

We knew there were hundreds of thousands of people who were energized initially by Jeremy’s leadership campaigns and would be excited by the manifesto. Mobilizing them to take that message to the public and present it in a way that would win people over was crucial, so mass mobilization was our objective. We have the biggest membership the Labour Party has ever had, bigger than any other left-of-center party in Europe. Half a million people can have an awful lot of conversations.

In addition, our social media operation was widely commended by people on the Labour right, and even by Tories. 25 percent of Facebook users in Britain engaged with at least one of our posts, which is phenomenal. And most of this was organic — not done through paid or targeted advertising. If what you’re producing is good enough, and at the right time, people will respond.

Our videos reached millions and millions of people, particularly young people. The ones focusing on how to register to vote certainly contributed to enormous rates of registration. A combination of mass mobilization and social media, including phonebanking, messaging, relayed WhatsApp messages and so on — people communicating with people they know — is a much more powerful way of doing politics than a career politician talking at you through your TV screen. We proved that in the election.

When you are trying to start a new organization in a short space of time, you are bound to have disagreements. That’s what we had. It’s unsurprising in such a large organization, especially with thousands of people, most of whom have not been engaged in formal party politics before. There are going to be different perspectives and there needs to be some working out done of your form and purpose. I think we started by trying to hold the coalition together but, actually, you can’t please everybody.

Momentum was not intended to be a political party, one that would have party structures. It was supposed to be an agent of change within the Labour Party, to turn the Labour Party into the kind of organization that is embedded in communities and workplaces, and therefore can reach the wider population in a way that it hasn’t done for decades.

But the reform of Momentum wasn’t without its difficulties. I think some of the things we had to do along the way were necessary and have been demonstrated to have worked in the election. That was our greatest challenge to date and, at the end, there is a broad consensus that Momentum achieved a lot. We’ve had people who’ve criticized us from the left, people who’ve criticized us from the right, recognize that.

When Jeremy was unexpectedly elected as leader, on such an enormous tide of support, people on the right of the party were in denial. That’s not surprising. They couldn’t understand, they became angry, and resisted what took place. We saw a lot of that over the last two years and it undoubtedly undermined our efforts to get our message across to the public. The division prevented clarity about our message.

I think we have now proven that mobilizing a large membership is the key to success. In order for members to win over the public you have to trust them and give them ownership of the project. You can’t do that without democratizing the party. So, the reform of the party must continue. Members must be engaged in policy-making, which has too often occurred at a distance, and selecting candidates, so that party activists can campaign in their areas with confidence.

The Labour Party is a broad church, and even Momentum is a pluralist organization. There are plenty of things we can argue about in a comradely manner. We don’t have to all agree on everything. The question is how do we build this diversity into the most effective body to represent people who suffer from inequality and injustice.

Tony was enormously influential on my generation and has had some influence even on today’s young people. It wasn’t that long before Jeremy won the leadership that Tony died, and he was always to be seen on the big demonstrations, so I think his ideas will still be influential.

What was crucial about Tony was that he learned from the experience of government, his politics were developed trying to change things. It’s been a long time since the Left was near government in Britain. It was marginalized by the New Labour leadership, so that there were hardly any significant left figures permitted. The ones that were got ostracized and weeded out over time. So, we don’t have that depth of experience anymore.

But we’re an international party, we need to talk to people in other countries who’ve had experience of governing from the left in recent years, and we need to use the best advisers that there are. We will learn some lessons the hard way, as we have the last two years.

I think what we’ve seen is that it is possible to win people over who see Jeremy articulating a transformation into a different kind of society. We have to hold that support and you can only hold that by continuing to organize in communities and workplaces, taking them along with you and explaining the challenges you face as they arise.

We will face opposition from all aspects of the establishment, from the powerful, from global corporations. That may sometimes require us to go farther than we have in the manifesto, and it may sometimes require us to find compromises. We have to engage our supporters in that discussion. The role of our movement in building and then maintaining trust is absolutely vital.