Alastair Campbell could not be happier to be in Australia next week.

“I’m really glad I am going to be there when the wretched charlatan Boris Johnson becomes prime minister,” he says. “I cannot believe it is happening. I cannot believe that is happening to our country.”

Campbell, who rose to prominence as former UK prime minister Tony Blair’s chief spin doctor, and is commonly thought of as the basis of Malcolm Tucker in The Thick Of It (although this is contested by Peter Capaldi) – has remained as outspoken on UK politics as you would expect of someone with his all-seeing reputation.

He has watched as Brexit has torn apart not just the conservative government but the country at large, and his own side of politics.

But on that, he doesn’t just blame the Tories.

“I think democratic politics is going through a very, very challenging period,” he says of the western world at large. “I think there are all sort of factors.

At the last election, Theresa May fought the worst campaign ever. It was truly awful. Alastair Campbell

“I think if I look at one big factor, for me, [it] is the crash, it is a consequence of the global financial crisis playing out, and the feeling that lots and lots of people around the world had nothing to do with it, didn’t cause it and they paid a price, and the people that did cause it didn’t pay much of a price at all.

“So that is one factor. The other factor, and I guess Trump is the sort of apotheosis [of this], and Brexit is part of this as well, is the sense of polarisation that isn’t just about left and right, it is also about cultural attitudes.

“And I think the media changes, not just social media, but the mainstream media has been part of this as well, with the 24/7 news and the way that has changed the nature of news. I think newspapers – not least the influence of Murdoch and others – I think that absolute politicisation, and polarisation of the news media debate, has been exploited and exasperated by populism.”

Campbell won’t just be in Australia to escape the expected coming of Boris Johnson. He was invited to speak at events hosted by Orygen and the University of New South Wales Centre for Ideas on the politics of mental health.

That’s another topic Campbell is intimately across. In 1986, he had a breakdown, which in 2008 he openly spoke about both in a BBC2 documentary, Depression and Me, and a book, All in the Mind.

He thinks more people should speak up about their own struggles, if only to help rid mental illness of the stigmas that still allow it to go unspoken or be cut from budgets. Even those in the political classes.

“I think you could argue that politics at the top level is something of a laboratory for mental health pressures – that doesn’t mean, by the way, that that is necessarily all bad,” he says. “One of the arguments I’ll make when I come to Australia and I do these speeches about mental health is when you are talking about top-level pressure and top-level performance, whether that is in politics, in sport, in theatre, in business or whatever, then that sense of ‘living on the edge’ feeling of knowing how to handle really intense pressure – sometimes the people who have had experience of real psychological turmoil sometimes can cope with that better.”

History has been defined by agenda setters who did great things, Campbell says, while simultaneously battling their own minds. Winston Churchill and his Black Dog. Charles Darwin and his agoraphobia. Florence Nightingale and her depression. Friends and family who keep going, despite life-long illnesses, such as Campbell’s own schizophrenic brother.

“What I think this mental health debate needs is a government in one part of the world that actually doesn’t just say ‘this is a priority’ but then really delivers on it, right across the sphere, so we have better mental health support in schools, we have better mental health support in [universities], we have better mental health services for children and adolescents, we have better acute care right across the piece,” he says, citing the Irish government’s decision to ban smoking in workplaces as sparking a worldwide wave of change.

“I think if you did that, over time, over a generation, you’d actually see that the healthcare system as a whole, I think, would end up saving money.

Alastair Campbell: ‘Brexit is tearing the country apart, the government is doing nothing else, the Tories are about to elect a complete charlatan.’ Photograph: George Cracknell Wright/REX/Shutterstock

“If we actually start to educate our kids about their mental health and wellbeing, including in schools, and also have a review of the criminal justice system – and this probably seems too Guardianista for a lot of people – but anybody who’s ever been inside a prison knows you do not have to go far before you meet somebody and you go ‘that person is ill, that person is sick, that person needs help’.”

Yet a failure to holistically deal with mental health issues has not been the only failure of governments. Campbell says he has watched as a form of “populist virus” has spread across democracies in the past decade, which traditional politics has so far struggled to address.

But progressives haven’t helped themselves in this shift, Campbell says.

“The other thing which has happened, and I feel this particularly in the UK, where, you know, we have gone from New Labour being, I don’t care what anyone says, a very successful government, three election wins with pretty big majorities, delivering lots of change, but unless progressives stand up for the record of progressives don’t be surprised if people think that actually there are easier way of doing things out there, and they then go for the populist message.

“And I think what we have at the moment is a populist virus.”

Which brings Campbell back to Johnson, who, at time of publication, is widely tipped to win the leadership ballot Theresa May’s resignation announcement sparked in May.

The recent televised debate between the party’s leading figures, Jeremy Hunt and Johnson, crystallised how populism had changed politics.

“I mean, we have gone from figures like Thatcher leading the Tory party to this being the choice,” Campbell says. “But also, it was the extent to which the really simplistic, populist, fact-free rhetoric was the stuff which was getting the applause. Where even five, 10 years ago, there would have been the absolute howl of ‘How are you going to pay for it? What happens if that doesn’t happen?’

“So the guy stands up and says ‘we’re leaving the European Union on October 31 come what may’ – well, how? With what consequences?

“What populism does – populism is not just about popularity and saying what people want to hear, it is also about having a date that if you like has nothing to do with fact or proper rigorous analysis and everything to do with emotion.

“And ultimately, that is unsustainable.”

But Campbell is unsure of whether the answer is a Bernie Sanders, or a Jeremy Corbyn, or even an Anthony Albanese – at least as he is described by his conservative opponents, who are trying to paint him as the Australian Corbyn.

I just wonder if they just decided ‘we are not electing Bill Shorten’. Alastair campbell

“I don’t believe you combat the populism of the right with a populism of the left,” he says. “What I fear is too many people on what you would say is the progressive side of politics, I think, have learned the wrong lessons about the [global financial] crash. I think there is a feeling that, as a consequence of the crash, the world, the public, moved to the left. And I am not persuaded that is the case. And if you look at what is happening in elections around the world, the opposite would appear to be the case.”

Launching that cultural war “risks losing those people you need to win [elections]”, Campbell says.

“At the last election, Theresa May fought the worst campaign ever,” he says. “It was truly awful. You look at where we are now – Brexit is tearing the country apart, the government is doing nothing else, the Tories are about to elect a complete charlatan as prime minister, and Labour – there was one poll recently which had Labour at 18%.

“Now that is not a media conspiracy, and it is not just because of Brexit. It is because they think progressive means keep moving to the left. It doesn’t. Progressive means ‘How do you make progressive change for the better by having a set of policies and values which are located where most people live their lives?”

Applying that same train of thought to the recent Australian election, Campbell says, from where he sits, he thinks yet another factor may have come into play – one which could also dictate the coming UK general election.

“I wondered about your election, because I follow it from afar, but I just wonder if maybe what happens – at a deeper level sometimes – a country sometimes makes a judgment about people over time, and I just wonder if they just decided ‘we are not electing Bill Shorten’,” he says. “And I think there is a risk they have done that with Jeremy Corbyn already.”

• Alastair Campbell will be speaking at The Politics of Mental Health in Sydney on Monday 22 July and in Melbourne on Tuesday 23 July. For details and tickets visit: orygen.org.au/about/news-and-events/2019/the-politics-of-mental-health