On the roof of Google’s offices in Kings Cross, Dizzee Rascal is excitedly taking in the London panorama. “Look, there’s Stratford,” he says, picking out Anish Kapoor’s Orbit sculpture before spinning around with puppyish excitement. “Canary Wharf … Alexandra Palace … Wait, where’s Wembley at?”

Fifteen years ago, Dizzee only really knew a tiny part of this city – his hometown of Bow, the place where he, with a little help from a school computer and a handful of peers, helped sculpt the sound of grime and changed the face of British music for ever. He was just 18 when his debut, Boy in da Corner, was released, a record that for once justified a music journalism cliche: it sounded pretty much like nothing else that had gone before it, a spray of ricocheting beats and lo-fi computerised bleeps that underpinned his lyrical gift for sharing the thoughts of an edgy, paranoid, smart, frustrated, vulnerable kid from a council estate. It was the sound of the future, of critical acclaim and awards. And then Dizzee went pop. By 2008, he had hooked up with Calvin Harris and embraced EDM; his fourth album, Tongue N Cheek, scored a string of No 1 singles. The boy from Bow, born 32 years ago as Dylan Mills, had conquered the city, and then the world. But hadn’t done so without his share of criticism: those saying he had sold out, abandoned his roots and headed too far down the pop mainstream. His follow-up to Tongue N Cheek didn’t help matters: 2013’s The Fifth saw him teaming up with the likes of Jessie J and Robbie Williams. It felt like his first proper misstep.

“A few people thought that, it’s cool,” he acknowledges. Hood pulled tight, he deals with questions like a boxer sparring in the ring: the answers come at pace and with the same forceful delivery that mark out his records. “I’m proud of those songs, proud that people play them at their weddings or that their two-year-olds dance to them. But you’re restricted when you’re making housey, electro poppy beats, and some people don’t necessarily take you seriously as a rapper.”

And so now on Dizzee’s sixth album, Raskit, and not for the first time in his career, there is a radical change of direction. “I made a decision that I’m not going to chase pop hits,” he says. “I wanted to go back to being as honest with myself as possible, not worrying about radio or that kind of shit.”

Watch the video for Dance Wiv Me

Certainly, there’s nothing here like Bonkers or Dance Wiv Me. In their place Dizzee delves into the fears he once had as a young rapper performing in the wrong postcode, frets about the precarious nature of fame (“Wot u gonna do, when it all goes sideways? Gotta work weekend shifts at Mac D’s, and you can’t party on a Friday”) and even tackles the housing bubble that is ripping up communities in the capital. On Everything Must Go, he goes as far as to sample such hip-hop luminaries as Margaret Thatcher and Boris Johnson, who turns up to promise us that London will never become ghettoised like Paris.

“I guess a lot of what is happening now started with Thatcher,” he says, showing me the book he is currently reading, Big Capital: Who Is London For by Anna Minton. “But it wasn’t about having a dig, it was about illustrating the story.”

Has gentrification had a negative impact on him personally?

“I’m from east London,” he says, as if the answer is obvious, but then adds: “I don’t feel like I have the right to say. You’d have to ask people who still live there [in Bow]. It’s all good going back, but then I can leave. It’s all good if you have a choice.” Dizzee currently lives in Kent – he is “done with the mortgage”, as he points out on Business Man – but he also spent a period living in Miami that, funnily enough, fired up an interest in politics he’d never had back home. “When we talk about the ghetto here, we have some harsh social conditions,” he says. “But over there, you’ve got third-world conditions – there are places in Miami that are no different to Jamaica or Haiti.”

Of course, Dizzee’s music has always been political, even if that wasn’t his main intention. Partly this was a matter of visibility – along with artists such as MIA, Dizzee represented a fresh, multicultural vision of British music – and partly it was through his journalistic approach to documenting the realities of estate life: on Hold Ya Mouf, Dizzee famously threatened to “remove you from your car”, before boasting: “I’m a problem for Anthony Blair.”

“And I’ve had it quoted back at me for ever,” he says, shaking his head. “It’s not like I’d sat down and knew all his manifesto. I was just trying to be a bit cheeky.” Dizzee used to say he had no time for politicians, and in that respect not much has changed: “I don’t go out of my way to try and be around them,” he says, “You have to look at their intentions or why they want you around.”

What about Jeremy Corbyn? Doesn’t he agree with fellow MCs JME and Stormzy that the MP for North Islington really is different to the others?

“I feel like maybe people feel the same [about him] as they did with Tony Blair,” he shrugs. “Although I was in the barber’s and the barber was telling me about a problem he had, getting his kid into a school or something. He rang his local MP and Jeremy Corbyn sorted it all out for him. So that’s what I’ve heard, firsthand. But as for #grime4corbyn and all that, I don’t know about it. What are their reasons for supporting him?”

I mention Corbyn’s anti-war voting record, his history of standing up to racism, his desire to help out poorer communities.

“See, I didn’t know any of that,” says Dizzee. “Was Tony Blair like that? I guess not. So Corbyn is more like Bernie Sanders or whatever, isn’t he?”

Winning the Mercury prize in 2003, aged 19. Photograph: Rex/Shutterstock

Politics, says Dizzee, is too knotty for him. Even dealing with gentrification led to a mix of conflicting thoughts: he can appreciate the new stuff popping up in his area; he worries that the original residents don’t get to feel the benefits; he wonders why they couldn’t have had it transformed while he lived there; he knows from experience that the computers he made his debut album on were donated to his school by businesses in nearby Canary Wharf – themselves a shimmering monument to inequality. “It’s not straightforward,” he says, which is why he would rather concentrate on music than attach himself to anyone else’s campaign.

Last year, Dizzee returned to east London for a rare moment of looking back, performing his debut album in full at the Olympic Park’s Copper Box Arena. At the time, he said the experience made him want to go back to making his own beats, and the thought of Dizzee returning to his roots got people excited. After all, while Dizzee was busy transforming himself into a global pop star, grime finally broke into the mainstream: Stormzy’s debut album topped the charts last year and Skepta picked up an Ivor Novello award. You would think that might make him feel pride – especially as new-generation artists such as Stormzy will happily bring him out to guest during their live shows – but he seems nonplussed by it all.

“It’s not new to me,” he says. “I’m probably the one person who can go against the grain and say: ‘Nah, I seen it, sorry!’ I know what role I played in it. I know loads of these MCs still use my lyrics, my flow and my sound and all that. But I’m here trying to make something new.”

In truth, Dizzee occupies a strange place in the scene. Like grime’s godfather Wiley, he still commands respect for his early albums – his role in grime’s development isn’t really disputed. But he no longer feels involved, and no longer seems to want to be. Does he not fancy making a grime record for 2017, one that sounds new? Skepta’s Konnichiwa or Stormzy’s Gang Signs and Prayer are albums that feel modern, after all. “No,” he says. “Gang Signs has gospel music on it!” He pauses for a rare second. “They’re current, but it’s what they’re doing. I’m trying to do something else.”

In fact, Dizzee did have a go at returning to his original sound, but says he found himself uninspired: “The beats were good but I’d done them before”. Instead, he decided to look back at grime’s earliest days lyrically, and from a perspective few other MCs could – a true scene originator. The new album Raskit features a trio of tracks – The Other Side, Make it Last and Ghost – that reminisce about a youth spent MCing on pirate radio and playing edgy raves. He says he wanted the tracks to serve as a reminder that the golden days weren’t as golden as people like to make out. On Make it Last, he talks about a double murder at the Tudor Rose in Southall in 2002, a west London venue Dizzee was playing at the time (“All I saw was G’s/Bredders on their knees/Screaming ‘Why d’you take my boy away? God help him, please’”).

“There’s a lot of talk of grime right now, but a lot of people don’t understand what that environment was like at the beginning,” he says. It could be exciting, but it wasn’t always as fun as it looked. It’s not like I had a job or a house [with a] picket fence. None of us did. And, back in those days, it was the kind of music that would make people shoot their gun in a club. People died at those raves.”

One reason Dizzee wanted to reminisce was as a way of settling scores with his critics. What he can’t stand, he says, are self-appointed grime scenesters telling him what he should or shouldn’t be doing with his music. More often than not, he says, it’s the hipsters who tell him he has sold out. “And they’re the ones that jump on to anything every five minutes,” he says, shaking his head. “People become mouthpieces or spokespeople for the scene. They’re dictating shit, but they weren’t there from the beginning. They like to talk like they were, but they wasn’t. A bunch of them raves none of these people were at. So it’s a clap back at my critics, people who are always questioning my moves.”

Watch the video for Wot U Gonna Do?

In Dizzee’s defence, those critics were often wide of the mark. Embarking on a pop direction was no less of a risk for Dizzee than anything else – not everyone can make it work, as evidenced by the attempts of several grime MCs to replicate his formula. One of the reasons Dizzee pulled it off so spectacularly is that he made it all look like a blast: he seemed permanently upbeat, and he could transfer that attitude on to his ever-expanding crowds. His songs changed focus to reflect his new life – one long holiday that involved dancing, drinking and copious shagging. “I was trying to make something nicer,” he says. “Of course I was having a good time – that’s what you’re supposed to do, innit?”

Success was a laugh for Dizzee, but it was also his escape route from a tense upbringing: he was expelled from four schools and often ran into trouble; shortly after winning the Mercury prize in 2003, he was stabbed by a rival crew member in Ayia Napa. Now, suddenly, he could travel freely, support his family, make a difference in people’s lives with his music. While some people feel more exposed through fame, Dizzee felt more protected and more focused. “I’d seen enough trouble, been in enough trouble, to know that I wasn’t really missing out. I just wanted to compete with artists, not anybody else.”

Did fame and fortune have any downsides?

“I dunno,” he says, before a grin spreads across his face. “You can’t slap people when they chat shit. That was easier back in the day.”

Last month, Dizzee followed up his triumphant Glastonbury performance, the fifth of his career, by pulling no punches. “They need to have me headline this thing,” he told the BBC. “They’ve had no British rappers headline this festival. They way I’ve tore [it] up for years. Never disappointed. You can always count on me. Put me on that main stage.”

“It wasn’t a rant, it just looks like one when it’s written down,” he says, before going off on a bit of a, well, rant.

“What more have I got to do now, innit?” he asks. “Because, sorry Gorillaz [who headlined in 2010 above him] did not get the reaction I got. They’re not as big as me, they’ve not done as much as me culturally, know what I mean? And, not being funny, but that set was sleepy.”

“Not to be rude, right,” he continues, “but I was on another stage while Radiohead headlined and they did not get the response I got. Let’s just be honest, if we’re gonna be doing that?”

Appearing at Glastonbury in 2010. Photograph: David Levene for the Guardian

Honesty is something he keeps coming back to. In many ways, it’s the theme of his new album – using beats he genuinely likes, telling stories as accurately as he can, making the music that is true to his heart. He wanted to make the best album he could, and has been trying to live clean of late, too, to keep his mind focused on the prize.

“I could just be a glutton – drinking, smoking, doing drugs – and I’d still be all right. Because, in rock’n’roll terms, people think that’s cool. But I want to stay focused. It’s quite boring, to be fair.”

Is that what a typical day is like for Dizzee now: all quinoa and Nutribullet kale smoothies? “Nah, there is no typical day,” he says. “Only that I wake up, eat, have a shower and sometimes have a shit.” He considers this last point carefully: “I do try to have a shit before I leave the house, because I don’t like shitting in anyone else’s house. But that’s the only thing typical about my day.”

Actually, he says, it’s people such as Calvin Harris – who followed up his collaboration with Dizzee on Dance Wiv Me with a meteoric rise to A-list fame – that inspired him: “He don’t smoke. Don’t drink. Don’t do nothing. Just super on it, super focused,” he says. “I was on his private jet and it was like rolling around with a fucking movie star, Brad Pitt or something like that! I’ve never seen women fall over someone so crazily, like, this is the same guy from Dance Wiv Me?”

He laughs: “He’s got a million-dollar studio in his basement. He’d pick me up in a golf cart at the door. I thought I was living the dream, but he is really living the dream.”

Dizzee looks out one last time across London’s skyline to appreciate his own dream. “It’s been a long career,” he concludes. “A lot of people have come and gone in this time, know what I mean? But I’m still steadily in the game, and that’s what matters.”

Raskit is released on Dirtee Stank Recordings on 21 July.

• This article was amended on 20 July 2017 because an earlier version said Southall was in south London. This has been corrected to say west London.

