Last year, when the grammar schools policy flooded media channels, Lewis Iwu stepped up to speak on radio, television and in campaign halls.

It was a moment he had prepared for most of his life and, having coincidentally become the head of Fair Education For All a few months earlier, he was perfectly positioned to be heard.

Set up a few months earlier, the FEA brought together a range of education charities – including Ark, Teach First, the Children’s Literacy Trust – and channels one voice in a “fight against inequality”.

Since 2014, charities have been “gagged” by new laws which mean they must waive their right to complain pubicly if they accept government funds.

When the grammar schools policy hit, it made life difficult for many charities who strongly opposed the move. Iwu stepped forward, with his plummy vowels, calm manner and persuasive oratory style.

If he comes across as Blairite-verging-on-Conservative-parish-councillor, it belies his history as a boy educated at St Bonaventure’s, the inner-city London school headed by the former chief inspector of Ofsted, Sir Michael Wilshaw.

I kind of liked the sound of my own voice at the time, and it felt grown up to have a voice. I became addicted

“A lot of people were scared of him. But I wasn’t,” Iwu says seriously, as we tuck into drinks and bar snacks in a pub in Greenwich, south London. “I had a lot of respect for him, but I wasn’t scared of him.”

Why were people scared? “I think because he had gravitas. He was always immaculately dressed. He carried himself with such poise and grace that he didn’t really seem like a headteacher. He seemed like some sort of politician.”

Iwu’s own slightly formal manner is unsurprising given the influence of St Bon’s (as it is known locally). At the time Iwu attended, Newham was one of the poorest parts of the country with some of the worst educational outcomes.

But Wilshaw always made his pupils act differently – immaculate blazers, polite language, an almost business-style approach. And the community loved it.

Iwu’s parents moved to the capital from Nigeria in the 1980s. His mother was a nurse, and his father ran a shop. Along with his younger brother and sister, the family lived on the 24th floor of College Point – a tower block not dissimilar to Grenfell.

Despite being of limited means his parents cared passionately about education. For his seventh birthday they gave him a set of encyclopedias. Iwu’s degree certificate now hangs on their living room wall.

But he found school frustrating – “being a cog in a machine” – and his school reports described a “bright but distracted” boy, until one day, when an angry teacher called Mr Farley accidentally changed his life.

“One of my friends was talking when we were supposed to be silent. He was about to get a punishment which was really unfair. So Mr Farley said, ‘okay, defend yourself. In fact, I’ll let you pick someone in this class to defend you and see if they can get you off the punishment’. For some reason, he asked me.”

Michael Wilshaw and Lewis Iwu

After 10 minutes of furious preparation, Iwu stood in front of the class and proclaimed that talking in classrooms was not always bad as it can help to repeat learning or clarify a point.

Mr Farley set aside the punishment and later asked Iwu to attend a new school debating club.

“I absolutely loved it,” he recalls. “It was exactly what I needed. It was competitive, I kind of liked the sound of my own voice at the time, and it felt grown up to have a voice. I became addicted.”

Competing at ever higher levels, Iwu eventually applied for the England schools debating team. A place was so unlikely that he never mentioned his audition until he received a place – and found out the international competition would take place in Calgary.

Trained at Cambridge by a Ph.D. student and former world-class debater, the team was comprised mostly of pupils from top private schools, including Eton. At Calgary, Iwu competed all the way to semi-final only to lose to Australia. The following year he got all the way to the final (where he lost to Australia, again).

The experience prompted him to apply to study Politics, Philosophy and Economics at Oxford, starting at the university in 2003.

Six years later, David Cameron complained that just one black student had been admitted to Oxford that year. The university issued a statement: the real number was 52. Out of more than 3,000.

“It was odd, I think I was literally the only black student in my college,” Iwu says, but he decided the best way to avoid misery was “embracing the bits of the world I hadn’t experienced” and “try to do something about the situation”.

He therefore got involved in student politics – eventually becoming the head of the Oxford University Student Union in 2007.

A racist incident, involving a squad of student rugby players dressing up as Orthodox Jews as a “joke” on a night out, threw Iwu into the media spotlight. It then emerged that some of the group had also “blacked up” for a safari-themed party.

“The media picked up on it. As the voice of students, I had to comment on it. I think it probably carried extra weight as a black student commenting on it. I came down pretty hard on them and my comments were pretty punchy,” he says.

“It’s awful when you work with an institution, and you get to see all the good things happening, their attempts to try and solve the access problems, and then a few idiots ruin it.”

With Nicky Morgan

Iwu dislikes being describing as a role model among his home community, yet it irks when he doesn’t see people who look like him in top roles.

“There is a particular type of black male that gets shoved down people’s throats in music and the media, but you don’t hear the counter-narrative. It’s refreshing to see a teacher, or someone in a charity, to show there’s more than one path.”

He can count on one hand the number of black men he has sat around dinner tables with during his time in education policy: “There’re hardly any. They are non-existent.”

Originally seduced into law after graduating, he later worked for the public affairs company Brunswick, which reawakened his interest in coalitions. As a child, Iwu was dragged along to a Nigerian community group, where people chipped in with dues each month to cover funeral costs if anyone unexpectedly died, or to help fundraise a hospital trip for a sick child.

When the Fair Education Alliance job cropped up he wanted to recreate that room, but for educational charities, so that issues could be debated and, crucially, solved.

We must not lose our ability to understand those who do not agree with us

He has now stepped aside from the organisation and gone back into corporate communications, but before he went, he wrote a book about debating in schools.

‘Words that win’ describes Iwu’s continued speaking endeavors – including competing in the world championships in South Africa where, in the morning, he went to a whites-only private school with two Olympic-size swimming pools before, in the afternoon, he visited a township school where 20 children sang the national anthem in the rain.

“I also taught debating at a maximum-security juvenile prison in upstate New York. I worked with 12 black boys. The least violent one had shot a police officer, but staff said it was the most animated they had ever seen them. It broke my heart.”

Iwu is convinced that teaching people how to use words so they can argue is one of the best ways to guard against violence – especially terrorism.

“So I’ve put together a book that explains how to do debating in schools well but also to explain why it is important for society, for democracy, for the economy,” he says.

“Right now too many people say ‘how could anyone vote for Brexit?’ or ‘how can anyone support Jeremy Corbyn?’ but there’s a lack of empathy on both sides.

“We must not lose our ability to understand those who do not agree with us.”

It’s a personal thing

What is your favourite book?
I’m going to go with the biography of George Washington by Richard Chernow. No, I’m going to change. ‘My Life’ by Bill Clinton. It’s a great primer on American politics, which I am addicted to.

What would you do if you were invisible for a day?
I’d be a fly on the wall in the British cabinet or a big corporate charity. I’d like to get a sense of what they are like when away from the public.

Which animal are you most alike?
I like to think I am an owl: quite bookish, and I’m getting wiser.

What would you not do even for a million pounds?
Sell a negative story to the media about my family or friends.

What’s the most exciting phone call you ever received?
From Jesse Jackson [the campaigner who stood next to Martin Luther King when he was shot]. Such a random story: I was at a restaurant in Chicago and next to us Jesse Jackson was having dinner with someone. I went over and said “I’m a big fan of yours”. We got into a conversation and he said, “let’s exchange numbers”.

The next day I got a phone call from him asking “do you want to come and hang out? Just come over to my office”. I went over and he was planning Rodney King’s funeral and then took me on the tour of a city. It was an incredible day.