Ed Miliband and I are sitting in his rather swanky corner office in Portcullis House, Westminster, talking toilets. Dual-flush, or Victorian-style with the satisfying pull-chain? Outside the window, the grandeur of the Houses of Parliament seems almost to rebuke us, but we don’t notice – we have important matters to sort.

Toilets, along with dog-grooming and how to sing like a death metal star, were among the subjects Miliband discussed when he stood in for Jeremy Vine on BBC Radio 2 for a week in June. And what a delight he was, merrily introducing songs by Queen (whom he mixed up with the Verve, but never mind) and making classic radio segues such as: “Northern Ireland gets more money from the government’s deal with the DUP – and I now get to meet the lead singer of death-metal band Napalm Death!”

Now he tells me in that unmistakable adenoidal voice: “The toilets were definitely my favourite segment. They were the most – I won’t say revealing, and one part of me was thinking: ‘Come on, I’m a serious person here.’ But they brought out another side [of me] and that was part of [why I was] doing it. People like a bit of humanity, don’t they? A bit of lightness,” he adds.

That’s certainly true. But, I ask, did he not realise that before he stepped down as leader of the opposition? Because lightness and humanity are not exactly what he was known for before, when he was seen as, well –

“What?”

An awkward Marxist nerd.

“Well, a nerd who’s the son of a Marxist might be more accurate,” he corrects, nerdily.

In the past year, the man once known as Red Ed has been getting his sass on. As well as playing Who Let the Dogs Out on Radio 2 after his dog-grooming lesson (“That was my idea! I take total credit for that,” he says proudly), he performed one of his favourite songs, A-ha’s Take on Me, on Channel 4’s comedy chatshow The Last Leg in April (“Oh, for fuck’s sake, talk about a midlife crisis,” the director, also played by Miliband, muttered at the end). He has also become one of Twitter’s more enjoyable tweeters. As leader of the opposition, his online patter was limited to “Join us today to help the final push of our campaign”; now he’s throwing shade at Piers Morgan, Donald Trump and his own former colleagues. When it was announced that George Osborne would be the new editor of the London Evening Standard, Miliband whipped out his phone. “Breaking: I will shortly be announced as editor of Heat magazine …” he tweeted.

So has he had a drastic personality overhaul in the two years since he stepped down following all that 2015 election unpleasantness? Was he badly advised to keep the real Ed under wraps when he was in the public eye? Or was the idea that he was a fratricidal geek just media spin, and he was actually a laugh all along?

“I’m the same person I was, definitely. But there are inevitable constraints with that job, and maybe I imposed too many more on myself,” he says.

Like what? That he couldn’t make jokes and have a personality?

“I think it’s less thought-out than that. I was aware of the responsibilities I was under, and that makes you more constrained than you might otherwise be. You’re running to be prime minister – it’s hard to be the person who makes jokes. I’m not in any sense comparing myself to Boris Johnson, but, you know, he’s got some issues because people think he’s ‘good jokes, no judgment’. It isn’t easy.”

Neither is it easy to have family in politics. The one thing everyone knows about Miliband is that he knifed his elder brother, David, by unexpectedly running against him in the 2010 Labour leadership contest, effectively ending David’s political career, and the two reportedly barely spoke for years after. But they seem to be speaking now, given that Miliband invited his brother on to Radio 2 to talk about his work with refugees. (Unfortunately, the phone line cut out halfway through their chat and so, once again, Miliband the Younger ended up shutting Miliband the Elder down earlier than expected.) So are they friends now?

“Yes. I mean, we’ve both moved on from the past. It’s been hard, and it’s never been … Look, what happened in 2010 happened, but he’s got this great job helping refugees, and I’ve got whatever job I’ve got and you know, um, yeah.”

It must be a relief to their mum that her boys are speaking again.

“Yeah. I mean, um – Yeah. Yeah.”

The windowsills of Miliband’s office hold photos of his family, including him with his sons, Daniel, now eight, and Sam, six, who was born less than two months after he became leader of the Labour party. These are, endearingly, almost identical to the one of Miliband as a child with his father, Ralph, a Polish Jew who escaped the Holocaust and became a Marxist academic, and whom the Daily Mail infamously described as “The man who hated Britain”. Above his desk is a photo of Miliband’s beloved Boston Red Sox winning the 2004 World Series (Miliband lived in Boston for a few years as a child, and then taught at Harvard for a spell), as well as a collage of photos from his time as a leader and a portrait of Keir Hardie. Miliband is taller than I expected – 6ft 3in, I’d wager. More handsome, too, although that mouth is straight out of Aardman Animations and with a tendency to wibble-wobble when he’s thinking, so it’s easy to see why there are so many unfortunate photos of him.

Ed Miliband (left) with his brother, David, in 2010. Photograph: Lefteris Pitarakis/AP

Does he ever think: “If I had just ordered a chicken salad instead of a bacon sandwich that day then I wouldn’t have lost the election, Brexit wouldn’t have happened, and we wouldn’t have the debacle of a minority Tory government propped up by the DUP”?

He shakes his head. “I think it can be overdone, the bacon sandwich. Maybe the bacon was overdone – hahahah!” (Some of his jokes are more successful than others.) “To say that was the reason we lost the election, I just don’t buy it. It was more complicated than that.”

So, does he have any regrets about his time as leader?

He pauses: “The bacon sandwich,” he says quietly, and then quickly laughs.

Miliband is not the first politician to engage in an image overhaul after stepping down from a high-profile role (he is still the MP for Doncaster North.) Michael Portillo set the modern template, when he morphed from being one of the most loathed Tories of the 80s and 90s into a respected TV personality after he lost his seat in the 1997 general election. But Miliband’s generation have thrown up some spectacularly unexpected makeovers – not least for Osborne. What does Miliband think of his paper?

“Jury’s out. He’s enjoying himself, and he obviously has personal animus towards May. But personally, I think he’s more responsible than he perhaps realises for some of the Tories’ problems. I mean, a lot of it is austerity fatigue. But if he can make the Evening Standard an interesting paper – and he’s certainly making it a talked-about paper – all well and good.”

The infamous Daily Mail story that smeared Ed Miliband’s father, the academic, Ralph Miliband. Photograph: Daily Mail

Two days before I meet Miliband I was at Glastonbury with his former shadow home secretary, Ed Balls, who had been greeted ecstatically by festival-goers, thanks to his time on Strictly Come Dancing. Was there a part of Miliband that looked at Balls’s newfound popularity achieved through light entertainment and thought, “I’ll have a bit of that”?

“Mmmm, not really. I think if I went on Strictly, it would make the bacon sandwich look like an elegant piece of style. It’s a slightly different situation – I’m an MP, he’s not,” he says, a little pointedly. “But good luck to him. I think you have to do these things in your own way.”

Indeed. Iain Duncan Smith, for example, took over from Miliband on Radio 2 for a week until Vine’s return and, by common consent, has been far less successful: “Miliband seems more likely to have a future in the studio,” Mark Lawson wrote in this paper. “Well, it’s an adjustment, you know,” says Miliband, sympathetically.

Looking back to when the media had the time to care about how the leader of the opposition ate a bacon sandwich is like gazing on another era. Since Miliband stepped down we have had the shock election of Jeremy Corbyn as Labour leader, then the EU referendum, then the Tory leadership madness, then the US election, then the recent general election upset. Does he feel politics has gone insane since he left the main field?

“I wouldn’t say insane, but it’s certainly fast-moving,” he says.

Surely the images of Corbyn being cheered like the Second Coming at Glastonbury must have stung a little. After all, Corbynmania knocks Milifandom into a cocked hat.

“Definitely not!” he insists. “You tip your hat to him, really. I think what Jeremy teaches me is that when I had instincts that we needed to break with the past, and we needed more radicalism, I was right.”

It must be frustrating to see Corbyn being so feted by young remainers when he is not even fighting against Brexit, though. Miliband, after all, was a firm remainer.

“No, I think he’s taken the right position on Brexit – I’m talking about post the referendum campaign,” he quickly adds. “Remember, I’m the guy who didn’t want the referendum – I wouldn’t have had it if I’d been prime minister. But you have to respect how people voted because this was partly about political alienation, so if the response to political alienation is to ignore it, that’s a recipe for more political alienation.”

So, how does he feel about Brexit now?

“Well, it’s a mess. It’s an absolute mess. I think the government has been incredibly cavalier and not honest with people about the payoffs, and they’re not prepared.”

Like they’re winging an essay crisis?

“Yeah, definitely.”

Did he feel any schadenfreude when that ultimate essay-crisis prime minister David Cameron stepped down?

He pauses for a few seconds: “Not really,” he says, which is not a no.

Have they stayed in touch?

“I’ve seen him once since he stepped down,” he says in a tone that suggests once is enough.

Ed Miliband on the Channel 4 comedy chatshow The Last Leg. Photograph: Channel 4 Picture Publicity

So having sat opposite Theresa May for so long, is he surprised at how disastrously it has gone for her?

“I don’t know Theresa May. I’m not sure that many people know Theresa May. I’m not that surprised, actually. But I’m surprised at how quickly it’s gone wrong for her, and no doubt some of it is personal, and some is political.”

One irony of the May premiership was her adoption of Miliband’s idea of an energy cap. When he proposed it, the Daily Mail accused him of taking the country back to the 70s. When May did so last month, it applauded her for standing up to the big companies. Miliband brings up this hypocrisy himself: “I mean, the energy price thing, [when I proposed it] it was Marxist madness, dah di dah di dah …”

It was Cameron who used that phrase in the Commons, I say, and when he did May was sitting next to him nodding enthusiastically.

“Did she now?” Miliband’s eyes light up delightedly. “Oooh! Good little nugget there! But then when she said it, the big companies said, ‘Are you joking?’ So now it’s: ‘We’re going to have a consultation and maybe not do it.’ This is not just a U-turn followed by a U-turn, it shows Conservatism is quite beached.”

Miliband has been specifically critical of May on Twitter for not standing up for Sadiq Khan when President Trump criticised him. How would he be handling Trump if he were prime minister?

“I think a lot more like Merkel and a lot less like May, because there are things that [May has done that] are just mystifying. Like, she refused to be part of that statement on climate change signed by the European leaders, and she refused to comment on the Muslim ban. There’s this thing in football – I’m not very good on football, but there’s a saying that you’re good at set pieces but you’re not very good when the ball is in the run and play. It’s like she found reacting to that quite difficult to do.”

We can talk about the Tories and Trump and how bad everything is all day. But, I ask, surely New Labour played a part in people’s desire to react against the establishment?

He looks startled: “What do you mean?”

Well, a lot of people are furious with Blair, they are still angry about the war and –

“Look, look, I think the Labour government did good and important things, and it’s really important not to undervalue them. I see in my constituency how it helped with education and all those things. I think part of the challenge to centre-left parties around the world is the extent to which they own the current settlement. I’ll take a Labour government over a Tory one any day of the week and I defend lots and lots of things the Labour government did, but did we get it wrong on inequality? Yes, we did.”

Anyway, it’s not bad, being an ex-leader. Like all former frontline politicians, Miliband talks about how much more time he now gets to spend with his family: he takes his boys to school most mornings and when we meet he has just come from a school sports day. “There’s a sort of absence [in the family] when you’re leader, even when you’re not absent. I’m trying to make up for it now,” he says. The family live in Dartmouth Park, north London, just a few miles from where Miliband himself grew up.

He married his long-term partner, Justine Thornton, the year after he won the Labour leadership election. Was this just to appease the media?

“No! No. No. We were always going to do it. I mean, it’s unusual to have the media at your wedding, but no. No,” he says.

I like Miliband. Really, it’s impossible not to. He is personable, funny, self-deprecating and knowingly wonky: when I ask at one point what he is reading, he shamefacedly produces something the size of a phonebook titled After Piketty.

Come on, he has to relax occasionally. What are his favourite TV shows and movies?

“Oh, God, I hate these questions,” he cries.

But this is how he can show his humanity.

“I know, but I just CAN’T,” he wails.

So, instead, we return to the comfort zone of politics.

“It’s very striking to me that Clegg’s gone, Osborne’s gone, Cameron’s gone,” he muses.

We talk a little more about the difficulty for politicians of showing their humanity while they are in office.

“Maybe Jeremy pulls it off more,” he says, as though the thought has just occurred to him.

Well, he was around for longer before becoming leader, I say.

“And maybe that’s to his advantage. I think it is. Yeah. Yeah, ” he says, and he sounds, to be honest, a little jealous. You can’t get more human than that.