The justice campaigner Gina Miller won two landmark legal victories that forced the government to be accountable to parliament over Brexit. Her autobiography, Rise, charts an extraordinary life of challenges faced and traumas overcome, including harassment and violence. She was born in British Guiana, daughter of Doodnauth Singh, who educated himself despite modest beginnings to become attorney general of independent Guyana. She has lived in Britain since she was 11.

In your new year Twitter message, you quoted Maya Angelou about the need “to step off the road in a new direction”. Is that how you feel?

I chose it because what I’m finding quite worrying is that – on all sides – we seem to be stuck in a rut psychologically, emotionally and intellectually. And that’s not a good thing. The time for reflection didn’t seem to happen over Christmas. Maybe people still need to vent the anger before we move on. But we still seem to be stuck in these silos.

Is the Brexit chapter over for you?

Brexit is going to happen. But my approach was always to insist that we mustn’t throw out our constitution with Brexit. The danger of that now is even greater, because we now have what could be a very autocratic government, with both opposition parties falling apart as they try and figure out their way forward. As far as I’m concerned, the battleground shifts. It’s no longer about Europe – it is actually about our country. How do we preserve Britain as a tolerant place when we don’t have Europe to blame for our problems any more?

One of the things that has struck me is how vulnerable our institutions might be in the absence of a written constitution – is that a likely focus of your campaigning?

Yes, you could say the American forefathers wrote their constitution with someone like Trump in mind. We don’t have that. So to my mind, we need to start a conversation about how we keep the flexibility of an unwritten constitution, but maintain certainty in human rights and control executive power. Is there something that can sit between a representative democracy and direct democracy, which gives people more say?

You obviously had high hopes for tactical voting to be more effective than it was in the election. Do you think it can ever work in our system?

Tactical voting in our country is not new. In 1997, it was very effective. But it only works when you have an alternative that people will vote for. We’ve now had our data back and what is extraordinary is the number of people who did switch – on both sides. People were very open to the idea of lending their vote. But what happened was there was a very significant shift [in voting intentions] on the weekend before the election. We still don’t know why. But on the Monday, we knew we’d lost and it looked like 30 to 40 seats. In fact, it was more.

What do you think happened – a wave of targeted advertising like that which Dominic Cummings used in the referendum?

We think something like that. We were listening very closely to all social media, using very sophisticated scraping methods, and this word “safety” started appearing in those conversations that weekend. Not “security” but “safety”, which is a very emotive word, particularly in relation to family. We still don’t know what the Tory campaign was – because if it’s being fed through the dark web or inside Facebook campaigns, we can’t see it. But that word kept coming up. People who seemed prepared to hold their nose and vote Labour were suddenly not prepared to do so.

Where were you on the night of the election?

I was on the BBC when the result was finally confirmed. The thoughts that kept going through my mind were: how is he going to deliver to this broad church of voters? And what happens when he doesn’t? How much more anger will there be?

They are not frightened of stirring up anger, it seems. They seem to believe that they can manipulate it.

I wonder how short-sighted that is. It is like winding up a spinning top: you have to eventually let go. You can’t predict how people will display their anger. If you no longer have the EU as the bogeyman, who will take its place? I have already seen many worrying signs that those perceived to be immigrants and foreigners are getting more abuse. I am getting emails from people who have lived here for 40 years and have been told in a supermarket queue to go back home. If you no longer have Brussels to blame, you start to blame the person next door. And then to have someone like Nigel Farage saying there is going to be this big celebration party on 31 January, this is all stoking those flames.

Mind you, if his previous celebrations are anything to go by, only a handful are likely to turn up…

That’s true. But the government is prepared to carry on this tokenism as well. They have the new Brexit coin coming out. Will we have a new plane for Boris emblazoned with the British flag, a new royal yacht commissioned? All that playing to the gallery just heightens those divisions.

Facebook Twitter Pinterest Miller makes a statement to the press after the supreme court ruled Boris Johnson’s decision to suspend parliament for five weeks last year was illegal. Photograph: Xinhua/Barcroft Media

You have been a lightning rod for a lot of those divisions and the subject of disgraceful abuse and threats. Are you able to walk down the street now?

No, I have to be really careful. I hoped that it would dissipate, but if anything it has got more ugly. I have stepped back from social media, but I keep an eye on it and there has been a huge increase in the number of people who are being extremely aggressive and threatening, both sexually and physically. A lot of them have no followers – they are bots set to try to stoke things up. I am very mindful that I could become a target for this. One of the things I disagreed with about the Remain campaign was that it allowed the other side to paint us as anti-Britain; we were labelled Remoaners or Chief Remoaners. All these campaigns should have stood up and said: “We are not moaners, we are defenders, we are defending our security and our economy and our democracy.” We allowed the other side to say who we were.

On a personal level, where do you see your energies being directed in the coming months?

I think towards those issues concerning the constitution and a more deliberative democracy. And then I will go back to the campaigns I was involved in that were put on the back burner with Brexit. Campaigns targeting the rise in domestic violence, the huge increase in violence against women on university campuses; and around special-needs provision, in particular for children approaching adulthood, who are increasingly locked away as if in prison. And then there is my ongoing work about transparency in the City and financial services, a lot of which I fear will now be scrapped.

You’re no longer a member of the Labour party, but how do you view the leadership election?

I would have backed Dan Jarvis, because I think he was best placed to unite the party. But of the people who have declared, I think Keir Starmer has the best qualities, though he seems more keen to prove his working-class credentials. We need someone who has the intellectual ability and responsibility when it comes to political language and nuance and Keir has that.

You talk in your book about learning to be fearful rather than fearless. What did what did you mean by that?

I’m often asked, you know, about being courageous. But I don’t wake up thinking: “Today I’m going to be brave”. More often I wake up and think “I’m so worried about this” or “I’m really frightened for my children”. I’m fearful that we that we could turn into a country where they have to feel second-class citizens or they want to hide the colour of their skin. Even my son, who is 14 and was born here, has been told “go back home”. So many divisions could be handed down in the next few years, which really could destroy our country.

I enjoyed the chapters in your book about your father, who seemed an inspiring figure. Would he have been surprised by what you’ve achieved?

One of the loveliest messages I’ve received I keep above my desk. It is from someone who practised law with my father in the West Indies. My father’s nickname was Doods. The card just said ‘Doods would have been very proud of you’. I worried when I was growing up that I wasn’t like other girls, because I sort of thought differently. I didn’t seem to be as emotional or cry as much as they did. And my father used to tell me: “Don’t ever worry about yourself, you are the way you are because you were meant to do what you are meant to do.” And so I think he always saw me as being someone who might do things.

Facebook Twitter Pinterest With Vince Cable at the Liberal Democrat conference in 2018. Photograph: Gareth Fuller/PA

Your book stresses the importance of learning from failure, but are you also able to think of yourself as a success?

I find it easier to deal with people being negative, in a way. I always find compliments uncomfortable. I don’t think I’ve done anything that great. I just did what I thought was right.

Apart from Brexit, the other thing that will dominate the news in the coming months is the Harvey Weinstein trial. As a woman who has experienced harassment and violence, do you believe that the culture he represents has changed?

I think the #MeToo movement is one of the most successful of global campaigns. But in the trial, I fear that his physical state will somehow engender some sort of sympathy that will take away from the monstrous things he did. Sexual violence is something you never recover from. It’s like a beautiful vase that’s been knocked over – you can put all the pieces together, but there are still cracks. And that’s what it feels like when you’ve been physically violated – the cracks are always there. So I sympathise with the women so much. I hope the trial is not conducted in a way that tries to destroy the women more than him.

You must be exhausted after the events of last year. Have you been able to give yourself a break?

My way of getting away is doing extreme things. I’m a bit of an adrenaline freak. The only way to switch off my mind is to do very physical things. So we had a holiday where I literally trekked all day, a serious backpacking holiday. And then I reread A Tale of Two Cities, which I find has so many echoes with our present moment. Even Dominic Cummings is in there.

Have you ever met him?

No I haven’t, but I know a lot of people who know him. He is an ideologue and those people tend to be trapped in their own psychological prison. What seems extraordinary is that we’re not only in this situation with a majority government – which means that basically anything can happen – but we also have, it appears, unelected advisers running our country who have an opportunity to execute their ideology. You have to worry about how pervasive that will be.

What was your New Year’s resolution?

Where I grew up, in South America, we don’t celebrate New Year’s Eve by looking to the future, we call it old year’s night. We celebrate having survived the year and still being safe. But I think this year has got to be about staying vigilant. And looking after yourself – because uncertainty wears you down. I do a lot of talks at schools and I’m going to use them this year to talk about empathy and kindness, those words that have apparently vacated our national conversation. We need to try to remind each other that most people are just like us.

• Rise by Gina Miller is out now in paperback (Canongate, £9.99). To order a copy for £8.79 go to guardianbookshop.com or call 020-31763837