Jeremy Corbyn sat hunched and tearful in his seat on a flight to Papua New Guinea, facing 20 long and lonely hours in the air trying to process the terrible news that his brother John Andrew was dead.
He was faced with the awful task of collecting his brother’s body and accompanying it to Australia, where John’s distraught wife and children were waiting to say their final goodbyes.
The politician says: “It was a brain haemorrhage, which was very sad. I just remember the sort of devastation of it.
“I went to Papua New Guinea to basically pick up his body and take it to his wife and children in Australia, where they were living. It was one of the most horrifying and horrific things to do.”
The loss of John, who was only in his 50s, shattered a little band of four brothers, who grew up in a village near Stonehenge, in Wiltshire.
Recalling how he had received a phone call with the news of John’s death in 2001, Jeremy explains the trip to Papua New Guinea carried extra poignancy because the brothers had previously travelled there together.
He says: “We were very close. It was so sad.”
Reflecting on the tragedy can only put the problems which Jeremy, 68, has faced since becoming Labour leader in 2015 into perspective.
In an interview with comedian John Bishop on W tonight, he discusses his loss, his childhood, and his children, but also his political views, and his refusal to let the abuse they bring get him down.
Jeremy, who joined Labour in the 1960s and first entered Parliament in 1983, says: “I don’t get involved in personal abuse.
"I’m not reducing myself to that level. If people don’t like what I wear, don’t like what I look like, or whatever, that’s their problem, not mine.
“I take up causes. I take up the cause of injustices and I campaign for them.
“And sometimes you get abused, sometimes you get denigrated, sometimes you get abused and denigrated. But it’s OK”
And it’s OK because he knows for every person willing to abuse and denigrate, there are plenty more who worship him. They turned out in force in June to very nearly push him to a shock election victory.
He says “at the moment” he has “no disagreement to the leadership of the Labour Party ”.
Little surprise after the success in June.
Jeremy, 68, has a self-belief rooted in the love and support he always had from his three older brothers and parents growing up.
Both his mum and dad were left-wing activists, and instilled in their son a passion for fighting for his beliefs.
He says: “My mum and dad were both very principled people on peace and justice issues. They met campaigning in support of the Spanish Republic in the 1930s. My mum was at Cable Street opposing the fascists.
“They were people of great principles. So, yeah, I got a lot from that.”
But they did not push their sons to enter politics – in fact, all his brothers went into “practical” careers.
He says: “They all went off to be engineers or scientists and I fell by the wayside. We were a very practical family in the sense that there were people making things all the time.
“My eldest brother decided he wanted to make a boat. OK. A boat.
“So everybody thought that was a great idea – until he started making it in the kitchen.”
His brother Piers is an environmentalist, who does not believe in man-made climate change.
Jeremy says: “My parents encouraged people to think for themselves, research for themselves and, above all, be practical at what you do.
“But all my brothers got good university qualifications. I didn’t.”
Instead, he left school with two “not very high” A-levels and went to do voluntary service overseas in Jamaica for two years.
He was so wrapped up in his volunteering he never even spoke to his family back home.
He explains: “It was a really formative experience of my life.
“And I made one phone call home in two years, but you know what? They were out when I called.”
He stresses that it was not down to a rift, but rather the technology of the day.
In fact, the family was so close, one brother was responsible for naming him.
He says: “I was supposed to be called something else. Mum and Dad agreed what I was going to be called, and he took the papers to go off and register the birth. And then he changed the name.”
His mum would never reveal what it should actually have been.
The Islington North MP, who lost both parents before he won the Labour leadership, says one of his earliest memories is of a family day out to Stonehenge.
He says: “My mum and dad didn’t like anybody being at home, they didn’t like anybody not doing something, so they dragged us all off to Stonehenge that day.
"They’d given me, even though I was probably about four then, quite a long lecture about the history of Stonehenge.”
Asked whether they would be proud now, he says: “They both were still alive when I was first elected to Parliament, so they were very pleased about that. So I hope so.”
Jeremy now has a close relationship with his own three sons.
One, Seb, has entered politics, and works for the Labour Party, but he has never pushed any of them. In fact Ben, the eldest, works in football, another of Jeremy’s passions.
Ben works for Watford FC, even though his dad is a diehard Arsenal follower and fan of manager Arsene Wenger.
Jeremy lives close enough to the Arsenal stadium to hear the crowd roar when they score.
He says: “There was that nil-nil draw the other week and I opened all the windows and there was nothing.
"I thought the match had been cancelled.”
While his sons may have different interests, they have all grown up immersed in politics.
Jeremy says: “The eldest one has been to every count, every election, since 1987, just after he was born.
"The first one he came to he was 10 days old. That’s cruel, isn’t it, really?”
For such a family man, a life in politics must have been hard to juggle at times.
But Jeremy has never backed away from contentious issues, whether it is getting rid of apartheid, scrapping nuclear weapons or attacking Tony Blair ’s decision to enter the Iraq War, an issue that angers him especially.
He says: “I think Tony Blair should be prepared to answer for the stuff that’s been put against him.”
Has it all been worth it? He says, simply: “I do what I do because I believe in it.
"I am proud to work for the community I represent, proud to do stuff to try to change politics, get a bit of justice, a bit of peace, a bit of equality.”
If he becomes PM, he would stand up to Donald Trump.
He says: “There’s a number of things I’d like to discuss with President Trump, and I will. Climate change for a start.
"I’d put my case to him. He, no doubt, would have a great deal to say to me.”
With his incredible, and unlikely, rise to the top, perhaps it is time a film was made about the unassuming chap who ended up being cheered by thousands on the Pyramid Stage at Glastonbury?
Given how he met his third wife, Laura Alvarez, originally from Mexico, it should be a rom-com, perhaps?
He explains: “Her niece had gone missing, disappeared, and I met her sister who was looking for her, and I then asked to help, and, of course, I did.”
So Hugh Grant to play Jeremy, the knight in shining armour, then?
He laughs and says: “Me and Hugh Grant are a bit different. I haven’t even got the hair for a start.”
- John Bishop: In Conversation With Jeremy Corbyn, tonight at 9pm on W.