Each morning when Jeremy Corbyn wakes, he does not, as one might suspect of the leader of a major political party, habitually turn on Radio 4 and listen to the Today programme, something most in politics do before they rub the sleep from their eyes. He will turn it on occasionally if there's something specific he wants to follow, but "by no means every day… We don't obsessively listen, as many political households do." Instead, he says, he will listen to Radio 3 or Classic FM. His wife of five years, Laura Alvarez, will often put on Magic and a morning turf war will begin ("We have a dispute about this").

He will not, as many politicians might, obsessively scan the morning papers, as he "doesn't particularly like to wake up like that". Instead, he will check the BBC website, quickly click on some others and simply see what aides have sent him by email. He won't turn on the TV and, indeed, is not always entirely sure what TV channels would be available if he did. Just recently, he says, he was hunting for Al Jazeera, only to be informed by his wife they don't have that channel. "I thought we had because we've got it here," he says, meaning his office.

© Marco Grob

It is a routine, he points out, "most households" have, which, depending on your point of view, is either refreshing (an everyman not obsessed with the Westminster bubble) or maddening (an idealist unengaged with detail and process), but rarely anywhere in between.

He will set off for work not, as he used to, on his Raleigh 300 bike - at £400, he tells me, it's the most expensive item he's ever purchased - because these days he tends to find himself mobbed and so will, instead, be picked up by an official car and allow himself to be spirited to Westminster and the offices of the leader of the opposition, offices that, after 32 years as an MP, he had never seen before he entered them as leader.

Corbyn's office is a small room, around three by three metres, with a single window that overlooks the Thames. It contains a desk, a small round meeting table with four chairs, a bathroom and not a lot else. It is not the traditional office for his post. That room - the one used by Ed Miliband and David Cameron, Tony Blair and Michael Howard - is a grand corner office just down the corridor, more than three times the size, plus balcony. It is now a meeting room.

Corbyn, ever the egalitarian, felt this office was too big for him; he felt, he told aides, "like a prisoner in a gilded cage". And so, after less than a week, he decided to move next door, to an annexe at the back of the main Labour operations office, into what is, by comparison, a glorified broom cupboard.

He will often catch up with his executive director of strategy and communications, Seumas Milne, who will walk from his office two doors down - one that wasn't supposed to be his either, he was meant to move into the Labour press office, but one he sequestered when he arrived that no one now holds much hope of him leaving - to the office of his boss, one several times smaller than his own, and the hostile takeover of Jeremy Corbyn will continue.

Just six months ago, the idea of Corbyn becoming prime minister seemed laughable. Just two years before that, the idea that a far-left backbench MP who had rebelled against his own party more than 400 times would be Labour leader seemed absurd. Yet, according to the polls, if an election was called tomorrow, Labour would win - and win comfortably.

To the delight of some, and the horror of others, Jeremy Corbyn really could be our next prime minister - and perhaps the most unlikely one in modern political history.

"And the great thing is," says the 68-year-old with a smile, "I've got the youth to do it."

© Marco Grob

It is impossible, in 2017, not to have an opinion about Jeremy Corbyn. He is a conversation-starter and a relationship-ender. He is a political Rorschach test in human form. To his detractors, he is an out-of-touch socialist peddling the same failed policies of nationalisation and vast public spending (the 2017 Labour manifesto detailed £48.6 billion, covering everything from scrapping tuition fees to increasing funding for schools, the NHS and the police force) without a clear plan for how to pay for it all. To his supporters, he is a rare politician in touch with the prevailing winds of anti-austerity and anti-establishment, who tapped into a general feeling that we are failing the generation to come and that technology, far from making the economy fairer, is hollowing it out: the rich are only getting richer; the poor are poorer than ever.

For both, it is essentially an argument about the significance of the past. Are Corbyn's idealistic supporters forgetting the economic reality of the Seventies? Or are his detractors naive in assuming that the failures of one era are still relevant four decades and a technological revolution later?

I meet Corbyn in his office in mid-October. He is kindly and soft-spoken and shakes my hand like a man who has been handed a particularly ripe piece of fruit.

"This debate is now about injustice and inequality," he says. "Two years ago, it would have been about benefits scroungers. We've changed the language and changed the mood. Labour is in good heart."

Corbyn never set out to be an MP, let alone the PM. Once elected, arriving in 1983 at the age of 34 alongside a 30-year-old Tony Blair, he stood for election to various committees but found little favour at any of them: "I stood for the parliamentary committee on a few occasions… I was not successful… I stood for the national executive… I was not successful…"

Mostly, he resigned himself to serving the constituents of Islington North and the politics of protest for various left-wing causes - the long grass, or the long game, depending on your point of view.

Even after he announced his intention to run in the 2015 leadership election, following Ed Miliband's general election defeat, there was no real expectation of victory: "If I'd have announced I was expecting to win, people would have looked at me funny."

The bookies gave him 200/1.

"To begin with, it was me and my credit card. That lasted a week. A few train tickets and hotels, it was gone." When the GMB leadership conference called and asked if he'd attend their hustings in Dublin, his reply was, "Who's paying for the ticket?" But slowly, the funding did come and the momentum built. He remembers one campaign event that took place on a Sunday morning at an arts centre in Nottingham. They expected a small gathering but found, half an hour before it began, people already spilling out into the street. "And we realised how strong our support was."

The route from dishevelled rebel to Candidate Corbyn has not been an easy one. A permanent protestor, he was never a natural leader. Early PMQs were bloodbaths. There have been widespread accusations that anti-Semitism - under the guise of Free Palestine politics - has become rife, without Corbyn doing anything about it.

Former journalistic colleagues of Milne's tell me that, in assessing potential leaders from the Labour left after Miliband's loss, Milne had been heard to dismiss Corbyn as "wholly unsuited" to the task.

Even altering his wardrobe, after Milne joined Corbyn's camp following his most unlikely leadership victory, was a struggle. In his first faltering Labour conference speech, his outfit of light-brown jacket and red tie was compared by the tabloids, not entirely inaccurately, to that of Mr Bean. On both of the occasions that I meet him, I notice his tie is balled up and spilling out of his jacket pocket, only to be worn when he is in the Commons Chamber and then taken off and balled up again when he is not.

I ask about the process of his team getting him to wear suits.

"It was a very painful process," he says. "The amount of blood that has been on this table… These arguments…" He looks across the table at the two press aides who are sitting in. "Put your hands up!" he says. He looks back at me. "There's been discussions. Heavy discussions. My sons are also involved."

Is it everyone against you?

"Yes… Yes… My only ally is a four-legged friend at home."

How many suits do you own now?

"Three," he says. "I bought them myself."

© Marco Grob

Like most things about Corbyn, the 2017 election outcome is a different result depending on who you talk to. For Labour, it was Schrödinger's election: it both was and wasn't a defeat.

On the one hand, from a prediction of complete wipeout, they gained 30 seats, increased the youth vote from 47 to 60 per cent, energised the left, gave hope to the disadvantaged and gave the lie to the dogma that to achieve from the left you must pander to the centre. On the other hand, well, they lost.

After the 2010 election, which saw Gordon Brown's Labour trail Cameron's Tories by 48 seats, Corbyn wrote in the Morning Star that the result was "disastrous for New Labour".

The 2017 election saw Corbyn's Labour trail Theresa May's Tories by 55 seats. Why wasn't that disastrous for Corbyn? "The popular vote was much higher," he says. "And in a sense that this election was a concentration into two-party politics."

Why does he think Labour didn't win? After all, in May, he was up against one of the most questionable Conservative leaders in decades.

He sighs and talks a little about it being a snap election and how the London media got carried away with Labour being wiped out, before saying, "Had the election campaign been slightly longer, I'm convinced we'd have got an overall majority."

Just that? More time?

"More time and at least a degree of reasonableness in the treatment of the Labour Party. Because the message that we're putting out on austerity hasn't fundamentally changed. There's been an enormous barrier in getting it across, but now I think a lot of people understand what we're saying and why we're saying it."

And now, of course, finally, the media are taking Corbyn seriously.

Before we meet, I sit in on PMQs and watch him take May to task over Universal Credit. It's a Labour win on the economy that the New Statesman describes as "the political equivalent of an away victory".

Yet it's fair to say it's the economy, more than any other issue, that divides people on Corbyn.

In the Labour manifesto, the eye-catching £48.6bn in spending will be paid for by, among other things, a tax hike for high earners and corporations. "Otherwise, what do we go with?" says Corbyn. "A perpetual decline where everything is charged for or is not available? Because we're not prepared to put taxation at the top end and for big corporations to pay for the services we need?"

Which is all well and good, but it assumes it won't scare off businesses, or even people, as happened in the Seventies. This time, Corbyn's Labour seems to say, it'll be different.

The manifesto also states £6.5bn will be saved by clamping down on tax avoidance, so I ask what he'd do regarding a company such as Amazon - a giant that keeps profits artificially low to price out its competition and gain market share. The result is that despite reporting a UK revenue of £7.3bn last year, it made a pre-tax profit of just £24 million. And, of course, it pays tax on the latter.

"You do it with a combination of tax havens," he begins, "and what they do…"

But particularly for Amazon's low-profit issue, I say.

"Amazon's case is… creating, as you say, an artificially low profit in one regime and an artificially high profit in another. Boots have done the same by…"

Sorry, I interject, that's not actually what I'm saying. I'm saying they don't create a high profit anywhere.

"You have to look at… a number of things… One of which is transfer of profits…"

But again, I persist, that's not what I'm asking about.

"In the case of Amazon… the issue of… the profitability of the company and the turnover is surely significant…"

So do you also tax on turnover?

"Well… we're looking at all of this. We don't have an answer on this at the moment. We're not pretending we have an answer on everything."

The worry with Corbyn is not, however, that he doesn't have all the answers. It's that, sometimes, he doesn't appear to have all the questions. He says he understands that the CBI will hardly be "rolling in the aisles when I tell them the level of corporation tax I think they should pay", so I ask who the business advisors of Corbyn's Labour are.

"Well, obviously that is done more through Becky Long-Bailey [the shadow secretary of state for business] and John McDonnell [the shadow chancellor] than me directly. They do have quite day-to- day relationships with unions and employers. I have met, and I will continue to meet, the CBI and Federation Of Small Businesses… Sometimes, actually, you learn an awful lot from meeting quite small but effective businesses and [seeing] what they do."

Sure, I say, but what about leaders of huge corporations? Are you asking for their input?

"They would be, yes. They are all the time."

But I'd have to ask McDonnell for the names?

"You would really have to ask him, more than me, yes."

Corbyn was born in bohemian comfort to parents David, an engineer, and Naomi, a maths teacher. They had both trained as scientists, but met at a meeting of the Spanish Civil War Redress Committee in Holborn, Central London. Corbyn would later say the "committed socialists" had met "in solidarity". His father, meanwhile, would tell Corbyn's brother Piers that he mostly remembered "her hips" and that "she wore a hat".

Corbyn and his three siblings grew up in the kind of large country houses that had names rather than numbers. Piers remembers the first, Hillside House, in picturesque Kington St Michael, Wiltshire, as drafty, a condition not unrelated to the fact that when they moved in, one side didn't have any windows. The second, Yew Tree Manor, in Shropshire, was grander still - when Corbyn's father purchased it, it was being used as a seven-bedroom hotel; it had its own grounds and a paddock.

The young Corbyn was energised but no academic. He attended the conservative Adams' Grammer School in Newport and did not fit in. The teachers went shooting at the weekends; Corbyn joined the League Against Cruel Sports. The pupils enrolled in the Combined Cadet Force at 15; Corbyn joined the Campaign For Nuclear Disarmament instead. His long life as an outsider had begun. He joined Labour the following year.

"At school," he tells me, "I seemed to be in a minority on every subject. Every argument that came up, every debate that came up, I was in a minority of one usually, sometimes two. That was quite character forming." Even when it looked like he might win a debate, it turned out he couldn't. According to Rosa Prince's unofficial biography, Comrade Corbyn, one rival, a prefect, threatened fellow pupils with detention if they didn't vote his way. Once again, Corbyn lost.

He sat his A-levels, but emerged with just two Es. The headmaster told him, "You will never make anything of your life."

He applied to Oxford Brookes, at the time a polytechnic, but was denied.

And so he travelled. First, to Jamaica, as a VSO, "working there at schools and theatres and camps for polio victims. Then I went travelling around Latin America on my own, which was probably unwise, particularly as I didn't tell people where I was going."

In two years, he called his parents once - they were out.

When Corbyn returned, he worked a slew of different factory jobs, mostly in the Midlands, before becoming active in the unions and immersing himself in causes.

I ask what experience has been most formative in shaping his world-view.

He tells me about a time, before the Syrian Civil War, when he visited a refugee camp on the Iraq-Syria border. It was miserable, wet and cold. Refugees had taken to trying to heat their tents with gas fires, only to set them on fire and burn alive inside them. He remembers speaking to a young girl, around 14, who had lost family members. Corbyn asked, "What do you want to do in life?" She said, "I want to be a doctor." "And I just thought, 'Wow.' There she was, in a position of utter hopelessness. Anyone else would say, 'I just want to get out of this hellhole. I don't want to live in a tent.'"

The lesson Corbyn took is this: "Let's not judge people by their situation."

Corbyn met his first wife, Jane Chapman, in 1973. The next year, they campaigned together to become Haringey councillors and were elected and married in the same week.

The trouble with socialism, Oscar Wilde famously said, is that it takes too many evenings - and Corbyn seemingly used all of them. Politics became his life, but left room for little else. "He was out most evenings," Chapman would tell the Daily Mail. "When we weren't at meetings, he would go to Labour headquarters and do some photocopying." His lifelong friend Keith Veness would lend him books, only to find them returned unread. Chapman would later tell the New Yorker: "He never read anything. All the books were mine." They divorced in 1979.

What are you reading now?

No Need For Geniuses, he says, a pop-science book by Professor Stephen Jones about scientific advances during the French revolution. It is not a book he bought - the month before, at London literary festival Archway With Words, he met Jones, who gave him a copy.

What about novels?

"Um, I'm not reading any novels. I'm just reading that."

Do you read novels?

"I'm not a massive novel reader. But I do… I like some of the classics. Graham Greene. I've always enjoyed Madame Bovary… And I like a lot of American and Russian novels."

What's the last American novel you read?

"Probably The Flivver King," he says, referring to the Upton Sinclair novel about the lives of Ford factory workers, published in 1937.

Anything more contemporary?

"I haven't read any recent ones. Maybe I should."

*What about your favourite film? *

He sighs. "I'm not a great cinema attender."

The last film you saw?

"I haven't been to the cinema in ages."

Fair to say you're not a film fan then?

"I mean, I don't mind the cinema..."

In retrospect, I'm not sure what's stranger about this: that Corbyn can't name a single film or that he appears to be under the impression he must go to the cinema to watch one.

He does occasionally, he says, read poetry.

"Throughout the two leadership campaigns I read quite a lot of Oscar Wilde," he says. I expect him to reference that socialism quote, but he mentions something quite different.

"De Profundis," he says, which, of course, is Wilde's letter written while incarcerated in Reading Gaol.

Why particularly Wilde and De Profundis during those times?

"Because he was a brilliant and conflicted person," he says. "Such a genius in many ways. So badly treated."

By all accounts, Corbyn came closest to quitting directly after the Brexit vote. Following a campaign performance that many Remainers felt was tepid at best - not least compared to the energised Corbyn who drew biblical crowds a year later for the general election - an astonishing eleven members of his shadow cabinet resigned on a single Sunday, one after the other, after Hillary Benn had been fired by Corbyn on the phone the night before, before he could officially quit himself. By the next day, another 28 frontbenchers left. By the end of the week, 65 had gone. It was the biggest mass-resignation in British political history. At PMQs, a visibly angry David Cameron, having already announced he would step down, admonished Corbyn at the dispatch box. Corbyn staying, he said, "might be in my party's interest. But it's not in the national interest. For heaven's sake, man, go!"

According to Tim Shipman's gripping account of the Brexit campaign, All Out War, Corbyn returned to his office looking like "a broken man". He is said to have turned to Milne and said, "That's it, Seumas. I've had enough." But Milne was not about to let him go so quietly. Over the next few days, Milne and McDonnell kept Corbyn in isolation, lest anyone should talk him into going. Even his son, Seb, was said to have pleaded with them: "Let my dad go." At the end of the week, Corbyn's aides briefed the Observer as to why they would not even let Tom Watson, Labour's deputy leader, meet him: "They want Watson to be on his own with Corbyn so that he can jab his finger at him. We are not letting that happen. He's a 70-year-old man. We have a duty of care." Apart from the fact they had got Corbyn's age wrong - he was 67 at the time - it only cemented what many in the Labour party already assumed. As Shipman writes, "The story contributed to the view in the PLP of Corbyn as a feeble leader surrounded by miniature Machiavellis."

Before I meet Corbyn, I contact a member of the Britain Stronger In Europe campaign, the official cross-party "Remain" campaign, which coordinated both the Conservative and Labour pro-EU efforts. In order to be candid, the individual spoke on the condition of anonymity.

Their office first reached out to Corbyn's in August 2015, a month before he was elected leader, "Just to say, you know, who knows what's going to happen with the leadership contest? We'd love to brief you on the campaign. And we didn't hear anything." It wasn't until the following March that they managed it, and with just one of Corbyn's staff. "So you're talking eight months to have a single meeting. Whereas with the broader Labour In team, we were speaking to them every day." After that meeting, they never had another. Despite that, I'm told, Milne "insisted on being the person who signed off on all the Labour In press releases".

My source is in no doubt as to where the blame for Corbyn's poor performance lies.

"The Labour In campaign was thwarted again and again by Seumas. It was Seumas. There would be quotes that they wanted signed off, or they wanted Corbyn to say a certain thing. Or they wanted Corbyn to do a TV clip. And it wouldn't happen. Or we'd be given a day where the Labour Party would be in the news and they just wouldn't put a plan together. Or the plan would change at the last minute and the broadcasters would get hacked off. And I know it felt like sabotage to Brian Duggan and Patrick Heneghan [Labour In's organisers]. That was what they said to us at the time. Sabotage."

In All Out War, Alan Johnson - the frontman for Labour In - gives a specific example: "We kept trying to get [Corbyn] to say, 'That's why I am campaigning to Remain in the EU.' It's a simple sentence. It kept going into speeches, and it kept coming out."

So, I ask, did that line get taken out?

"I don't know what he says was taken out."

"That's why I am campaigning to Remain in the EU…"

"I don't know what he's talking about. I stood alongside him in St Pancras Station and said exactly that about why I'm campaigning to remain in the EU."

So Milne wouldn't have taken that line out?

"Well, I said it, so it can't have been taken out. I think it's extremely unhelpful and unfair for him [Johnson] to have said that."

After the interview, I struggle to find the event where Corbyn told me he said the line. I check in with his office and they send me a link. It was 22 June - the day before the referendum.

Corbyn has never shied away from pointing out the EU's failings. As far back as 1975, during the referendum vote on Britain's membership of the European Economic Community - what would later effectively become the EU - he voted against it and, like most of Corbyn's opinions, the suspicion is he has not appreciably changed it since.

Yet, with a Labour membership that is 90 per cent Remain and a support base that is 70 per cent Remain, politically, he had to at least be seen to be trying. The frustration stems from what he could have done if he'd actually tried.

"You look at the contrast with the general election, the thousands of people that he had out at rallies around the country," says the Stronger In insider, "and you wonder why he couldn't have done that at the referendum, why he couldn't have brought that energy. Because I think it would have been transformative, actually."

Notoriously, in an appearance on Channel 4's The Last Leg, Corbyn said he was "seven, seven-and-a-half" out of ten on remaining in the EU. A ringing endorsement it was not.

"I recognised there were failings in the EU," he tells me now. "Failings of bureaucracy, failings of remoteness, and people were very angry about it. I, nevertheless, felt we should remain and reform the EU. Had the vote gone the other way, I would now be pressing the EU to reform on State Aid, to reform on investment. A lot of things."

Do you genuinely feel you did everything you could? That nothing was left in the tank?

"Two thirds of [Labour] voters supported the view taken by the Labour Party," he says simply. "I campaigned to lead the party on that position."

Corbyn has gone on the record to say that he personally voted Remain. But several members of the Remain campaign I spoke to told me they strongly suspected that his key advisors - Milne and Andrew Fisher - voted Leave.

So, I ask, what did your top team vote?

"I think they all voted Remain," says Corbyn. "I haven't asked them."

You haven't discussed your Brexit votes with your key advisors?

"They all, as far as I know, campaigned for Remain. Yeah, they did."

But, I persist, are you really saying you never once asked your director of strategy - the man who was in charge of your Brexit campaign events and speeches - which way he voted?

"I wouldn't dream of asking him. As far as I'm concerned, we're here to develop a political agenda. That's what I'm doing. I don't ask my staff any personal questions."

© Marco Grob

To watch Corbyn give a speech is to understand him. But not for what he says, necessarily, more for how he says it.

It's just after midday at the main conference hall in Brighton in late September, and I'm standing in the wings. Corbyn is set to give what many hope will be a rousing conference speech. Advisors are in buoyant mood. This time last year, they say, it was terrible. "Everyone had wanted Owen Smith to win," one tells me, gloomily. But now, of course, everyone loves Corbyn. Everyone really loves Corbyn. There are Corbyn cups and Corbyn posters, Corbyn bags and Corbyn badges, Corbyn T-shirts and even Corbyn colouring books. And there is, of course, a Corbyn scarf with "Oh Jeremy Corbyn" knitted in. Many, despite the late-summer heat, have their scarfs with them.

Over the past three days in the conference hall, as the various speakers have taken to the stage, it hasn't taken much to set the crowd off. Often, his name doesn't even need to be mentioned. "And we owe it all to one man," someone on stage will say, and it begins, loud and in unison, like an invisible conductor has just given the signal, to the tune of "Seven Nation Army" by The White Stripes: "Ooohhh, Jeremy Corbyn… Ooohhh, Jeremy Corbyn…"

Even when someone makes the opposite point, it doesn't make a difference. "It's never down to one person," says one speaker. "And I think he'd be the first to…" But before the point is made, he's drowned out too. "Ooohhh, Jeremy Corbyn… Ooohhh, Jeremy Corbyn…"

Many in the press will call it cult-like, but I think this misses the point. It is no surprise it's a football chant and no coincidence it comes on a scarf. They are, simply, adoring fans, and with all the lack of critique that brings. If you support, you support unconditionally; in Corbyn's fanbase, as in Corbyn himself, there are no shades of grey.

If, to the membership, New Labour felt like they were cheering foreign imports, then now, finally, they get to cheer one of their own.

At the Daily Mirror party the night before - one of seven Corbyn would pop into - the band will play "Seven Nation Army" as he enters. At the Momentum event that same night - one people queued around the block to get into - he will arrive on stage in a fog of dry ice ("I must say, I quite like the idea of a meeting starting with a fog of dry ice," Corbyn later tells me).

Yet, to have a personality cult you first need a personality. Corbyn's appeal, meanwhile, is his lack of one. How can he be selling a lie? He's not even a salesman.

At the stage's side, his advisors come and go. Despite rumours he was preparing to quit, his head of events, Gavin Sibthorpe, author of the infamous "Sibthorpe Doctrine" ("The best way," he told a Vice documentary in 2016, would be to let Corbyn "fail in his own time") is here. As is James Schneider, the youthful former Momentum frontman, dressed head-to-toe in black, and carrying an A4 document case that's also black, save for a single Labour-red popper. He paces from backstage to the rear of the hall, then back again. Milne does the same, but he doesn't so much pace as glide. Backstage, there is a small room with a Labour podium to practise at, but I'm told Corbyn has his own personal one at his hotel room. At 11am this morning, his team suddenly realised the speech was too long and so had to swiftly cut 1,000 words. There was no time for another dry run. Finally, to rapturous applause, Corbyn takes the stage. The crowd are in thrall, but he is an odd public speaker. Corbyn either talks softly - almost a whisper at times - or he shouts, with almost nothing in between. He's either patiently explaining or angrily railing, but never, it seems, cajoling. This becomes clear when he talks of the shifting centre-ground in British politics.

"It is often said that elections can only be won from the centre ground," he says. "And in a way, that's not wrong. So long as it's clear that the political centre of gravity isn't fixed or unmovable. Nor is it where the establishment pundits like to think it is."

Put another way: Corbyn doesn't need to move to the centre, the centre will come to him.

"We are now," he says on stage, "the political mainstream."

To his supporters, it is his biggest strength. To his detractors, it is his biggest weakness. There will be no compromise, no pandering. He is, in many ways, the first social media leader - a symptom of the age of social media bubbles, where people get to hold their beliefs close, where they are calcified and never questioned. To question orthodoxy is to be labelled a Tory or a "centrist dad", someone stuffy and out of touch. But to rule, to get things done, so the thinking goes, compromise is all. Politics, the saying goes, is the art of the possible.

What are your thoughts about the "centrist dad" tag?

"I'm a centrist dad," he says. "Radicalised!"

Have you made any compromises since becoming leader?

"Um…" he says. "We have had some problems, as everybody well knows, and I have not always had my own way. On the Syria vote, for instance, I didn't have my own way. But I was not prepared to countenance the bombing of Syria, so I did what I did."

Or, put another way: no, he has not made any compromises.

It's also for this reason, I'm told by a Labour insider, he has not had a single conversation with Tony Blair since becoming leader.

Is it true? Have you not met Blair?

"Nope."

Is there a reason for that? After all, he is a Labour leader who won three general elections.

"Nope. I've had no conversations with him at all."

If he reached out, would you speak to him?

"I'd talk to anybody. I'm very polite."

Right. But would it not make sense to get the advice of someone who has won elections?

"I've made it clear my views on austerity and I've made it very clear my views on the Iraq War. And I promised that I would, and I did, give the apology on the anniversary of Iraq, and I stand by that, because I think it was a catastrophic mistake."

Can you ever forgive Blair for Iraq?

"It's not a question of forgiving. It's a question of understanding the enormity of that decision. And I look back at the points that we made in the run-up to the war and the words that I used in a big rally in 2003, in which I said, 'This war will unleash terror.' And look what's happened."

Once again, the talk of the conference had been anti-Semitism in the Labour Party. Yet, despite specifically mentioning the horrific racist abuse suffered by Diane Abbott, and decrying "any abuse of anybody", he does not mention anti-Semitism by name in his speech.

Wouldn't it have made sense to?

"It was right to recognise the abuse a black woman has faced," he says. "And it's abominable what Diane and other black women have been through. We agreed with a huge majority the new rule on racism - which includes anti-Semitism and Islamophobia and other forms of racism. I have made my position on anti-Semitism abundantly clear on many occasions and I felt that the speech was set in the context of our society and how we oppose racists. I was at a public meeting on hate crime two weeks ago in Islington, at the mosque in Finsbury Park. Three hundred people came. Absolutely horrendous, harrowing stories of individual abuse. And we know the abuse Jewish people go through in public. We know the abuse Islamic women go through in public. We know the abuse young women go through in public. It's all wrong. I made that very clear."

He did, he says, catch May's speech - but only in brief. He was cycling through Norfolk at the time, "and Laura picked bits and pieces on her phone and told me about it".

Did you feel sorry for her?

"Yes, because it is a big gig, as you might imagine. But you actually begin to feel sorry for those around her. And what you realise is that it's a huge amount of effort put in by your team."

Back in Brighton, Corbyn ends his speech by saying, "Many hadn't voted before, or not for years past… We offered an antidote to apathy and despair." He says, "We will not let you down" and that Labour "can and will deliver a Britain for the many and not just the few".

The auditorium rises to its feet for a standing ovation. Corbyn, a fringe protestor who has suddenly found half the country protesting with him, beams and waves. The crowd, once again, begins to sing, "Ooohhh, Jeremy Corbyn…"

Before I leave, we talk about what a first day of Corbyn at Number Ten would look like.

"Well, there's a huge in-tray…"

The first thing would be the housing crisis. Then refugees ("We cannot go on ignoring the numbers of people that are forced to become refugees of war, because of environmental and human rights issues). Then, of course, "precious things", like saving the NHS.

Despite his stance on nuclear disarmament, he would, he says, allow himself to be briefed on the nuclear codes ("Of course I'd be briefed on them"). He'd also speak to Putin. "I am strongly critical of Putin's government on human rights issues. Does that mean we don't have a relationship? No, it means the opposite." And he would meet with Trump. "I look forward to meeting him and I hope we can work together to deal with the crucial issues faced in the world, on environment and climate change, on refugees, and on a longer trajectory for peace. It depends how the conversation went. And I would then talk about human rights and ask him specifically about some of his views, including the wall in Mexico - which Congress looks like it doesn't want to fund anyway, so it might not happen."

We talk a little about sections of wall Trump has built for "testing".

"I think it's for the public to go down there and choose which type of wall they want. Or you could tick the box saying, 'None of the above.' Have you seen it? Quite bizarre, isn't it?"

The biggest danger, he says, "is the inability of world leaders to speak to one another".

Before I go, he shares a story.

The previous Saturday, he says, he and McDonnell were at a campaign event in Great Yarmouth. Afterwards, they went for a walk on the beach. Corbyn spotted an otter in the sea and scaled up a huge rock, one that was more than twice his height, to get the best picture. At this point his press secretary covered her face in shock. "Jeremy! We'll have to get you insured!"

Nevertheless, Corbyn shows me the pictures he took on his phone. "It's amazing quality, isn't it?"

McDonnell, meanwhile, stayed on the beach, and beckoned him down.

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© Marco Grob

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