Shortly after he emerged on to the political scene at the beginning of this decade as the youngest MP in the House of Commons, David Lammy, now 36, was dubbed “the black Blair”. Then, perhaps because he didn’t rise through the government ranks quite as fast as some had wildly predicted, or simply because this was a trite epithet, it fell out of use. In recent months, he has been nicknamed, equally glibly, “the British Obama”. When he is the only black male member of the Government, says a friend, to call him this is “demeaning”.

Nevertheless, Lammy and Barack Obama share more than their skin colour. In a few weeks’ time, Lammy could be the best-connected politician in Britain, thanks to a friendship with the Democratic candidate that predates his run for the presidency. Both have compelling personal stories and have made unlikely journeys to political prominence. Raised by single mothers, they thrived in academic environments and developed a strong religious faith and sense of morality that informs their outlook. Although they operate in different political cultures, they articulate vividly some common messages about inclusion in a way that seeks to transcend race.

Lammy, who was promoted in the recent reshuffle to Minister of State for Higher Education and to the Privy Council, met Obama in 2005 at an event for black alumni of Harvard. “I saw him every time I went back to the States. We stayed in touch. We had a lot to talk about, a lot in common. He was a senator in the biggest democracy in the world, I was a minister in one of the biggest democracies. Our cultural backgrounds were similar. We built up a professional friendship.”

Listening to Lammy talk, one can almost hear him and Obama shooting the breeze, late into the night after those alumni dinners. Like his friend, he has the lawyer’s ability to deconstruct an argument, the professor’s love of sending new ideas up the flagpole and the pastor’s ability to convey his arguments with passion and eloquence. He is a heavy man, with a slightly lumbering gait (he jokes at one point that he has to go to the gym because he would “love to eat cheesecake all day, and then I’d look more and more like Forest Whitaker”), but his verbal delivery can be as quick and punchy as a blow from a heavyweight boxer.

He is cagey when talking about Obama. Gordon Brown was forced to deny breaking the convention of foreign governments remaining neutral in the presidential race after he wrote an article praising Obama that failed to mention John McCain. “I’m reluctant to talk about personal conversations,” says Lammy. “What I would say is there is a shared experience that’s wider than just David Lammy and Barack Obama. We met at a black-alumni event where there’s a shared experience of coping at the top of your game, of being a minority, and also perhaps an element of trust. I think Barack and I have struck up a mutual respect and trust.

“Of course, what is happening with the Democrats in America is exciting.” He reels off a list of prominent black political leaders he knows. “Obviously, with those politicians, with that dimension of black heritage, it’s particularly interesting for me because I haven’t had role models in Britain in that context.” He attended the Democratic convention – “It was wonderful, really wonderful” – but adds: “I’m slightly constrained here. I have to accept that I’m a minister in the Government. Ask me in November.”

The common version of the David Lammy story is “boy from the ’hood makes good” – but it is more complicated than that. Born to first-generation Guyanese immigrants, he is the youngest of four boys and has a younger sister. He visits relatives in Guyana every year and sends money back. (“They haven’t got shoes. They live in shacks.”) In Tottenham, his family lived in a terraced house on the periphery of the Broadwater Farm estate, which became famous after the riots in 1985 that led to the death of PC Keith Blakelock.

His father left when he was 11. “He went to America. I never saw him again. There was no time to get bitter or upset. My father was a good man, but crumpled under the pressure of fatherhood and responsibility. I don’t judge him for that. I got on with it and had a very strong sense that we mustn’t go under as a family. My older brother came to parents’ evenings with my mum.” He used to speak to his father on the phone occasionally, but there was no inclination on either side to meet before his recent death.

His mother, Rose, also died earlier this year. “It was a tough time for all of us. We were very good friends. She worked very hard.” His mother juggled jobs, including one at Camden Town Tube station and one as a home help, and “was an ambitious woman for herself and her children. Education was incredibly important to her. We spent hours in WH Smith buying rulers, protractors, compasses, comprehension books… She would set tests and go out to work in the evening and come back and expect the test to be done. She was pretty strict. This was in the days before the smacking ban.”

Church was important, too, and young Lammy was in the choir. This led to what he calls his “Billy Elliot moment”: winning a scholarship to the King’s School, a state school in Peterborough that provides choristers for the cathedral choir. “That was a huge watershed for me.” Before then, he says, he could count the times he went further from Tottenham than Holloway. Peterborough “felt very far away. It was far away emotionally.” He was stunned by what he found. “Commentators have taken the mickey out of Peterborough, but I thought it was beautiful, and the school had fields. I hadn’t really been exposed to fields.”

He was the first black chorister at the school and suffered racist bullying. “Some of the kids used to scratch the golliwog off the Robertson’s jam jars and put my name on it. It wasn’t easy. But I made some wonderful friends, friends I still have. It was a Christian, very pastoral environment.”

Trevor Elliott, deputy head of the school, recalls that “David really struggled” with the demands of being a chorister and a highly academic workload. He was a late developer whose A-level results “didn’t suggest he would go to Harvard and be a government minister”. But he was “a delightful and engaging young man” who was made head boy – “His leadership ability was burgeoning, rather than the finished article.” Lammy says that school awakened his interest in politics and social issues, starting with: “Why do some kids get this and others get something completely different?”

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