The morning after the UK’s general election, Syima Aslam and Irna Qureshi were sitting in the cafe they refer to as their living room, picking their way through huge plates of prawn kebabs. Of particular interest among the previous night’s results, which saw Labour strengthen its hold on their Yorkshire city, was the one in Bradford West, where a vicious sectarian campaign ended with an increased majority for the sitting MP Naz Shah.

Shah, like Aslam and Qureshi, is part of a British Pakistani community that now accounts for more than 20% of a Bradford population once dominated by Jewish wool traders. Although nearly all of the Jewish community have since moved to Leeds, they have left their trace in the “little Germany” district of 19th-century converted warehouses, built of handsome Yorkshire stone, that sits at the heart of the city. Their place has been filled with successive waves of immigration, from south Asia, Africa and eastern Europe. In 2010, Bradford became the third UK “city of sanctuary”. It is home to more than half the Syrian refugees so far accepted by the UK, says Aslam proudly.

It was against this backdrop that she and Qureshi teamed up in 2014 to found the Bradford literature festival, a 10-day cultural jamboree in which an evening of traditional south Asian wedding songs sits side by side with a steamy session on erotic bedside stories, and comic book superheroes compare pulling power with more local heroes such as the Brontës and JB Priestley.

Three years on, they run a year-round operation with seven full-time staff, including themselves – all but one of them women – from their HQ on the University of Bradford campus. They have upended the traditional literary festival model and attracted a demographic that is the dream of all forward-looking funders. Of the 31,000 people who attended last year, 48% were from black and ethnic minorities, and 8,000 were schoolchildren. They have found audiences for Sufi philosophy as well as Irish history and Islamic boy bands. Their programme stares down racial intolerance and religious bigotry, while making space for free-for-all weekends of fairytale and wizardry in the city park.

Egyptian author-activist Mona Eltahawy, who will be returning to the festival this year, says: “Too many literary festivals are by and for white, upper-middle-class people, as if the rest of us don’t read or appreciate literature. The Bradford literature festival is a necessary antidote for those of us who are neither. It is one of the most truly diverse and representative I’ve ever spoken at. I am obsessed – and it is my life’s work – with complicating the image of Muslim women, and I love that fact that two British Muslim women of Pakistani descent who love poetry and who are from Bradford have done exactly that through this wonderful festival.”

Talk to Aslam and Qureshi, and it seems everyone you most admire is somehow connected to Bradford – or if they aren’t, they soon will be. Playwright Andrea Dunbar, once dubbed “a genius straight from the slums”, is among those to be celebrated this year with a screening of Rita, Sue and Bob Too and a talk by its star George Costigan. If Dunbar’s semi-autobiographical comedy represents the enduring deprivation of some Bradfordians (the sell for the 1987 movie was “Thatcher’s Britain with her knickers down”), a more glamorous, albeit mythical, past is suggested by a strand of events on King Arthur. “I was flicking through Twitter when I saw a tweet about how Camelot wasn’t far from here,” says Aslam. It didn’t take much sleuthing to link up the author of the tweet – Simon Keegan, the author of a series of speculative bestsellers – with Peter Field, the emeritus professor of Arthurian literature at Bangor University. The result is a strand of events ranging from a discussion of Camelot through the ages to an Arthurian glass-painting workshop.

While Aslam was born in Halifax and moved to Bradford during her primary school years, Qureshi is Bradford born and bred. Both are bilingual second-generation immigrants in a community so tight and traditional that Aslam’s mother has never found it necessary to learn English – but, says Aslam: “To assume that because people don’t speak English means they are illiterate is a massive misapprehension. My love of books came from being taken to the library at every opportunity because my mother knew how important education is.”

This is not to underplay the very real problems of a 21st-century city dealing with a rapidly growing population. By 2020, half of all Bradfordians will be under 20, according to James Fergusson, the author of a recent book, Al-Britannia, My Country. Fergusson devoted a chapter of his study of Muslim Britain to this city of 125 mosques, some converted from churches, a cinema, even an old textile mill. “And yet nowhere is more evocative of northern England’s glorious and not so glorious industrial past,” he writes. But he also pointed out that its schools are way down the league tables, crime and poverty are rife, and that while he was doing his research in the city in 2016, a gang of Asian men from nearby Keighley were jailed for trafficking vulnerable white schoolgirls for sex.

Both Aslam and Qureshi have written about their own complicated negotiations with their cultures of origin. Aslam adopted the hijab in adulthood and wore it for 11 years until friends persuaded her that it was holding her back in her sales and marketing career, while Qureshi has written movingly about the failure of her arranged marriage to a cousin in Islamabad.

On her blog, Bollywood in Britain, Qureshi recalled her mother’s struggles to be accepted in Bradford because of the strong local code of loyalty known as “biraderi” practised by the majority Pakistani population of the city. They arrived in the 1960s from a valley in the Mirpur district of Jammu and Kashmir that was submerged when the massive Mangla dam was built. A generation after the exodus, Qureshi wrote: “With bonds of biraderi in full force, being Pakistani wasn’t enough, it seemed. In order to be truly accepted, you had to belong to the same clan from Mirpur; and we weren’t even from the same region.”

One of the achievements of the festival is to capitalise on the porosity of the city, and the paradoxical parochialism of its many communities. Poetry plays a big part in the programme, and they are not afraid of allowing it to be spoken in its language of origin – whether that is Punjabi, Parsi or Polish.

It is not a coincidence that our meeting is booked for lunchtime. Hospitality is another important part of their vision. “Food is important,” they chorus. It was what first brought the two together after Qureshi, an anthropologist and oral historian, turned up at the restaurant Aslam was then running to interview her for a book. “She fed me and I liked what she was doing,” says Qureshi. Over choice dishes from the Indian-Arabic menu, they discovered a wealth of shared interests, ranging across film and literature before settling on the photography of Peter Sanders, the one-time rock’n’roll snapper who now devotes himself to capturing the Muslim world.

Sanders will make two appearances at this third festival, which will open its doors on 30 June to “400 writers, 300 events, 10 days, one city”. Aslam and Qureshi started with ambitions that seemed as unattainable as the holy grail: to create a festival that had something for all of Bradford’s many ethnic groups, which was free to anyone who couldn’t afford the price of a ticket, and yet paid all its contributors. Equally fanciful appeared their aim to create a “destination festival”, capable of attracting international stars of stage and screen to this unglamorous northern city for more than just a single event.

“We are always looking for ways to draw people in who might never have been to an event before,” says Aslam. If that involves 100 candles and scatter cushions to lull the audience into feeling they are lounging in their own front room, then it will be done.

It also involves coaxing participants to go beyond their usual sales patter. “While most festivals are about the latest books, we want go further and find out what else interests them. We’ll talk about the books, sure, but our speakers are like fair-trade ingredients: individually sourced,” says Qureshi. Keeping up with the fizz of connections can be dizzying, but who wouldn’t be intrigued by sessions linking Japanese samurai to George Lucas’s Jedi, Dante to our current political inferno, or sex bots to the future of humanity in an era of declining birth rates?

Their revels will end, as always, on a contemplative note, with an evening of sacred poetry at Bradford cathedral, where the Anglican bishop will host a Bhajan singer, a Buddhist poet, Sikh shabad kirtan performers and a Christian gospel choir. No translation needed.

• Bradford literature festival runs from 30 June to 9 July 2017.