The first UK party leader who was born in the Eighties, the first woman to lead the Lib Dems, a former minister in the David Cameron-Nick Clegg coalition, it must have felt very different four years ago, when both she and her husband, Duncan Hames, lost their seats as Cameron finally won a majority. She admits it was a little bit like grief after a death. But a year later, thanks to his disastrous referendum decision, Cameron was gone; then hubris struck his successor, Theresa May, who called an election expecting a landslide, which instead saw her lose the Tory majority and Swinson back as MP for East Dunbartonshire (a seat she first won as a 25-year-old in 2005). Two years later, she was elected Lib Dem leader. As Cameron and May reflect on their failures and mull their place in history, Swinson is now in a potentially critical position in the stormy politics of our time, as the fight over Britain's future continues to rage.
Alastair Campbell: What does it say about our country that Boris Johnson is prime minister?
Jo Swinson: I think it is deeply worrying. Six or seven months ago, I didn't believe that the Conservatives would elect Boris Johnson. I think what happened was they got spooked by the Brexit Party.
AC: I wonder what it's saying at a deeper level about what our politics is becoming. Is it about showbiz? Is it about journalism?
JS: I think we're at a moment of shift where the old fault lines of British politics between the left-right spectrum aren't where the debate is anymore. It is now about this liberal to conservative, or authoritarian, spectrum. Whether you have an open or closed view of the world.
AC: Would you argue that both main parties are there?
JS: They're both split and that is why they are both struggling. That's one of the reasons for the increase in support for the Liberal Democrats at the ballot box. Tens of thousands joined the Lib Dems since the start of May because people want someone that speaks to those small "l" liberal values for opportunity, internationalism, equality, fairness, treating people as individuals.
AC: Say Tories and Labour got identical outcomes in terms of seats, which of Boris Johnson and Jeremy Corbyn do you think you could work with as prime minister?
JS: They are both, I think, not fit to be prime minister.
AC: If that is the choice?
JS: There are millions of people out there who agree that Boris Johnson and Jeremy Corbyn are not fit to be prime minister and so we have a general election campaign and we make our case and our pitch to the country. I think the way that politics is right now, things are volatile. I think we are at a tipping point because we are changing from that old system, where it was all about left-right and those two big parties and people want some new and something different.
AC: As you know I voted for the Liberal Democrats in the EU elections...
JS: Thank you very much, Alastair!
AC: But if you're going to stop Brexit, there are going to be lots of areas where presumably you will want Labour to beat the Tories?
JS: I know that there are people in the Labour Party, who are working hard and trying to get Labour to a sensible position on Brexit. But basically we both know that the Labour leadership is not currently in favour of Remain. We don't know what the manifesto is going to say. It doesn't matter whether you put a red rosette on it or a blue rosette on it, Brexit is going to be bad for our country. People deserve, I believe, to have the choice to vote for a party that will say we should stop Brexit.
AC: You and Labour are hitting each other into the low twenties and you're in danger between you of setting Johnson up for a winning position, where he then has a mandate for a hard Brexit.
JS: I think that our politics and the public need a clear choice of a party that is unequivocally backing remaining in the European Union. The Liberal Democrats are that party.
AC: Do you differentiate between Corbyn and Richard Burgon and Ian Lavery, and the Peter Kyles and the Phil Wilsons and the Anna Turleys?
JS: I have a very positive working relationship with lots of Labour members of parliament, and indeed Chuka Umunna joined the Liberal Democrats. He has talked about how it was like gang warfare in the Labour Party and he is struck by how positive and welcoming it feels in the Lib Dems. I know there are many former Labour members and voters who have come to our party and I think there will be more. That includes people who are currently in parliament.
AC: I see you at meetings of the People's Vote campaign. We're not going to get one without the Labour Party's support.
JS: That is why we have to work cross-party. I think the Remain cause needs a very strong Liberal Democrats at the centre.
AC: Do you think we'll see at the general election a bigger version of the Brecon by-election where parties stand down from each other?
JS: My instinct is there will be some more of that. It's not new. At the last general election. We didn't stand in Brighton Pavilion against Caroline Lucas of the Greens and there have been various local arrangements. There will also be a lot more tactical voting. We have a broken voting system.
AC: Johnson's not going to change it is he?
JS: I think its days are numbered. You have a system which has been for so many years geared towards two main parties, but those parties do not work within the new landscape of political opinion.
AC: From a purely selfish Liberal Democrat perspective, would it worry you if Jeremy Corbyn vanished and somebody more credible came in?
JS: I'll certainly say there have been many times over the last couple of years when Jeremy Corbyn stood up at the despatch box and said something and then 20 minutes later Yvette Cooper is called from the backbenches and you just think, "Yep, she's showing you how it's done." History is littered with what-ifs. What if those Labour MPs hadn't put Jeremy Corbyn on the ballot paper and somebody like Yvette had become leader of the opposition? We might have been - would have been - in very different territory. I think you'd have had a Labour Party that would have enthusiastically campaigned to Remain at the referendum in 2016, which I think might have meant you'd have had a different result given it was so close in the end and you'd certainly have had a different past three years in the aftermath.
AC: Is that where a lot of your antipathy to Corbyn comes from, failing to campaign in the referendum?
JS: Brexit is part of it. That Panorama documentary where you saw those staffers, young people... Instead of saying he would root out the anti-Semitism and going to war with anti-Semitism, he goes to war with the BBC and impugns the reputations of those former staffers. I do find that really troubling.
AC: Does Corbyn not care? He does have a world view.
JS: Does he care about anti-Semitism? That is the genuine question you are left asking.
AC: You mentioned Caroline Lucas earlier. What do you think of her woman-only cabinet idea?
JS: I'm a big fan of Caroline. We get on very well and we agree on a lot of things.
AC: I can feel a "but" coming.
JS: She made a contribution about how we work more cross-party, and I am a huge feminist, but I think men have something to offer the debate as well. There's the but. When I first entered parliament, women were about one in five MPs. Now it's up to about one in three. We've all had that experience of being the only woman in the room and knowing what that feels like to feel a bit different. There is a degree of shared sisterhood that is sometimes unspoken and silent but acknowledged.
AC: What did you learn from losing, when you and your husband both lost on the same night?
JS: Yeah, it wasn't a great day in our household, though when we had the vote to leave the EU it felt much worse. I was in the situation where most Lib Dem MPs lost their seats, most Scottish MPs lost their seats, so as a Scottish Lib Dem MP it helped not to take it too personally. Certainly, Duncan and I supported each other, but also our colleagues were in the same situation. There was a degree of shared experience about it. Obviously, it wasn't in the plan, losing, but I do think in some ways it ended up being positive, because you often learn more about yourself when things don't go well than when they do.
AC: Now you're party leader, with the possibility of an election just around the corner, or a referendum, with a new baby as well...
JS: You make things work. If I think about the state that our country is in, its actually because of Andrew and Gabriel that I'm really motivated as well. I took Andrew to the Extinction Rebellion protest. He's five-and-a-half. He can understand that. In Cornwall we went to the Eden Project, where they had some really good stuff about climate change in a way children can engage with and understand. I think that's important because the voice of young people in these debates is crucial. If we don't act now in the next decade, what future are we going to hand on to then? If we don't win this fight to stop Brexit, think of all the opportunities that they are not going to have that my generation and your generation had.
AC: We're the same generation.
JS: Yeah, obviously.
AC: Me as a child of the Fifties, you as a child of the Eighties. What does it say about politics that Greta Thunberg has become such a symbol?
JS: I think it's a positive thing and also a sign that things are broken. It is genuinely positive because young people should be listened to. I was the youngest MP when I was 25, 14 years ago. I kind of hated being called the baby of the house, but I always felt that we should have young people involved in politics. Often young people are quite patronised in politics, so I think it's fantastic Greta Thunberg is leading this fight, that the School Strikers For Climate are doing the same.
AC: What do you think it says that so many people seem to want to do her in?
JS: That is part of the way in which public debate is at the moment. I read this brilliant book last year called Ten Arguments For Deleting Your Social Media Accounts Right Now.
AC: You haven't done that.
JS: I did pause for three months while I was on mat leave and it was lovely.
AC: Didn't do anything at all?
JS: There was one exception, a day in early December last year when there was lots of stuff that was going to happen on the Brexit vote and I thought I need to know what @BBCLauraK is saying. But, no. I didn't do any posting on Twitter or Insta for three months. It was very positive. The whole premise of the book is that the way the business model works is about getting our attention and then selling us stuff and manipulating us and that has negative impacts on our politics and the echo chambers have a negative impact on our debate.
AC: But you need it for campaigning.
JS: That's why I did it on mat leave, but as an active politician that is not very practical.
AC: There is a lot of talk about anger. Should we not be a lot angrier over the state of our politics, the state of our government, the state of the world?
JS: I think people should be a lot more active than they are. We are seeing more of that, because that anger can be channelled in a positive way. We saw it after Trump's election. Lots of people, women in particular, given what he had said about sexual assault. We did see elected a fantastic new generation of women. All is not lost. There is hope. People all have power. Some of us have more power than others. Some of us have more privilege and are better able through having more money, or a position, or a status, or influence. Everybody can do something; nobody is entirely powerless and if we work together, we can achieve a huge amount.
So much happened in the immediate aftermath of our interview that we spoke again at the end of a week in which Boris Johnson lost more Commons votes than Tony Blair did in his entire Premiership, and lost his brother Jo from the cabinet too.
AC: The first part of our interview was the day you had the first meeting with Corbyn and the other leaders. You've had more. Has your assessment of him changed at all?
JC: It is still frustrating, to be honest. There is not always the urgency I think there should be. But I think we got to the right place in resisting the calls for an election. I am not scared of an election but I believe the People's Vote is the way to resolve Brexit, on its own, not mixed up with everything else.
AC: Who is more flakey on maybe falling into the trap of an election for their own reasons, Labour or the SNP?
JS: It is complicated. There are lots of different motivations at play. We are working together on this at the moment, so I am not going to be overly critical. We had another call today and Anna Soubry, Caroline Lucas, Liz Saville-Roberts and I were absolutely clear: we should not be playing Johnson's game, letting him have an election on his terms just because he can't do the job. He was desperate for the job. He was going to get a great deal. He is not even trying. He has got to the hot seat and been shown up for what he is. It is not our job to help him.
AC: Mrs Thatcher won a huge majority in 1983 on roughly the same share of the vote as Theresa May got in 2017 - because Labour and the SDP split the opposition vote. Do you not need to make sure there is a lot of tactical voting and arrangements maybe about who stands where?
JS: We are very clear we want to stop Brexit and anyone who wants to stop Brexit should vote Lib Dem.
AC: Even if it splits the vote in seats where only Labour or SNP might beat them and helps Johnson win?
JS: On Brexit, it is not clear what a vote for Labour will mean. I have a lot of time for those people who have worked so hard to get them to a better position, but they are still talking about delivering Brexit and the only clear path against that is us.
AC: But you accept the risk?
JS: We did not stand against Caroline Lucas last time. There are discussions we are engaged in through Unite to Remain, but in the vast majority of places the best way to stop Brexit will be a Lib Dem vote.
AC: Corbyn has moved on a referendum.
JS: Kicking and screaming. He had the opportunity to lead the charge and failed to take it. We are going to be better funded, target more seats. It is very difficult to predict what will happen. This is a four-party election, if and when it comes. The Brexit Party is still a player.
AC: We both agree a referendum is the best way to resolve this but do you see an election as inevitable now?
JS: I think we are moving to an election, the question is whether it is in weeks or months. Once you have a government without a majority it can't hold that long. You could have an emergency government led by a grandee that could command support across the House. Currently the Labour leadership is not open to that but that might change.
AC: Who was it who shouted "sit down darling" when you were speaking in the Commons?
JS: I don't know. I didn't hear it, but was told afterwards. If I'd heard it, you'd have heard about it.
Read Alastair Campbell's full interview with Jo Swinson in the November issue of GQ, out on 4 October.