As the world around him gets madder by the day, the process of creating satirical collages has kept Christopher Spencer sane.

The artist known as Cold War Steve, whose image of Brexit Britain sinking beneath the Thames graced the cover of Time magazine this month, could have “gone on Twitter and ranted”. Instead he used the social media platform to share his versions of a Hieronymus Bosch-type hellscape.

“I know from my Twitter audience they are completely dismayed by what’s happening – not just Brexit, but Trump, the rise of the far right, the increase in hate crimes. But there’s something quite powerful about laughing at these people, flaying them alive with humour and sarcasm,” he told the Observer.

Time magazine 17 June 2019. Photograph: Time

In a few days, Spencer will unveil a giant collaborative artwork at Glastonbury, where three years ago the music festival went into collective shock as the result of the Brexit referendum sank in. He has produced a book of his work, The Festival of Brexit, and has begun selling limited edition prints and giant postcards of his collages. But Twitter, where he interacts with 176,000 followers, remains his favourite showcase.

His work features public figures in typically English settings – seaside towns, low-cost supermarkets, working men’s clubs, car boot sales, a nostalgic place of “Fray Bentos pies and insipid high streets”. Among the Brexit cast list are Nigel Farage, Boris Johnson, Michael Gove, Theresa May, Jacob Rees-Mogg, Jeremy Corbyn and the Queen. An international presence is supplied by Trump and North Korea’s Kim Jong-Un.

There are also a handful of figures who epitomise Britishness – Cilla Black, Noel Edmonds and, most notably, Phil Mitchell, the EastEnders character played by Steve McFadden. Mitchell appears in almost every collage created by Spencer.

“He’s an everyman, an observer, the hero of the pieces, the anchor to the real world. He’s me looking on in disbelief, really,” said Spencer. He has never had contact with the actor, “but surely someone must have pointed out that he’s on the front of Time magazine? I’d like to think he’s got a copy in a drawer.”

The Time commission came out of the blue as Spencer was shopping for tartar sauce in Asda. “I’d been thinking I’d like to do something in America, it’s such a rich seam, but I didn’t know how to get a foot in the door. Then this email came, asking me if I’d be interested in doing an illustration for Time. The next day they said they wanted it to be the cover of the international edition. It was mind-blowing.”

Spencer, who usually creates his collages on his phone, often on the bus on his way to work as a probation officer, had never before worked to a detailed brief. “It was very specific. They wanted lots of cliched British references – Westminster, Big Ben, London taxis, red buses. But I thought, this is Time magazine, I’m not going to be precious.”

He had concerns about whether his “quintessentially British humour” would work in the US, and whether his loyal Twitter following would regard the commission as “selling out”. And he was unprepared for the lengthy negotiations with Time’s editors on the detail of the illustration.

“I’d get the proofs back, with someone’s face circled and the question ‘who is this?’ They didn’t like the naked mole-rat coming out of a sewer. They said the image I’d chosen for May was too cruel. They asked for Harry and Meghan to be included; I’d never have put them in myself. And they wanted Sadiq Khan in, even though I kept telling them he’s one of the good guys. So I put him in flying the Trump baby blimp, though his hand is obscured by Roger Daltrey.”

He worried that he was compromising too far in “heated negotiations”. But he insisted on keeping Phil Mitchell and Cilla, and had Prince Philip driving the bus (“I’m not sure they got the joke”). “In the end I was happy with the result. I mean, it’s the cover of Time!”

Spencer, 44, grew up in a socialist family in the West Midlands. His father worked at the British Leyland car plant in Longbridge; his mother later became an English teacher. He loved art as a child, but after his application to study fine art at Wolverhampton University was rejected, he had a series of jobs in factories and warehouses. Over the years, depression and alcoholism took a hold, and in 2016 he had a “complete breakdown” and attempted suicide.

After a period in hospital, he began to make collages on his phone and sharing them on Twitter. “It was a coping mechanism. If I was creating things, I could focus my mind on that rather than crashing anxiety attacks.” Cold War Steve – a series of images of Phil Mitchell/Steve McFadden superimposed into cold war scenes – “definitely helped my recovery”. He has not touched alcohol for more than three years.

‘If I was creating things, I could focus on that rather than anxiety attacks.’ Photograph: Antonio Olmos/The Observer

Then came the Brexit referendum. “The day after, I sat on the sofa like a husk. I could have had a relapse, back to drink and stuff, but this outlet was there for me. It certainly helped me get through it.”

Spencer has raised money for the mental health charity Mind from his work, contributing around £10,000 so far from sales of postcards, Christmas cards and other items. “I’ve never before been able to have any influence. Mind helped me, so as things have started to pick up, I wanted to do something – both financially and promoting discussion around mental health issues.”

I don’t know what I would do if couldn’t satirise these repellent, grotesque imbeciles Christopher Spencer

He is currently on unpaid leave from the probation services. “It was getting quite hard to juggle a stressful job with this.” His wife Katy works long hours at a care home, and the couple and their three daughters live in a small rented house in Sutton Coldfield. Katy “keeps me grounded”, he said, and his eldest daughter, who is 13, finds her father’s new public exposure “totally embarrassing”.

Spencer still sketches out collages on his phone, but now uses a tablet and laptop to finish his pieces. He works at a small kitchen table, listening to the radio – BBC 6 Music and James O’Brien on LBC – and occasionally drinking a can of Red Bull.

He draws inspiration from the medieval Dutch artists Bosch and Pieter Brueghel. In the foreword to his book, the author Jon Savage also references two historical satirists. “In his sharp moral sense and his ability to create his own complex, detailed worlds, Spencer is the contemporary equivalent of [William] Hogarth or [James] Gillray, both unsparing satirists and social chroniclers,” he wrote.

“Future social historians will find much beneath the Brexit headlines if they study these works: they will find an anatomy of contemporary England – or, to be specific, one particular part of its anatomy, the arse-end – that might help explain the delusion that has descended on the land.”

As Spencer spoke to the Observer, the results of the first ballot of the Tory leadership race came through on the radio. “I don’t know what I would do if couldn’t satirise these repellent, grotesque imbeciles. From the point of view of creating art, it’s a fantastic time, there’s so much material.

“But thinking of my daughters growing up in this world is frightening – a small, shrinking island, bitter little England. I just hope good will prevail in the end.”