'Oscar snub? It's the audience that matters'

Oozing the eloquence and poise you'd expect in an influential leader, the British actor is no stranger to public speaking either, having cut his teeth at the Royal Shakespeare Company.

"Night after night, you're giving incredible speeches written by the greatest playwright of all time to hundreds of people," says the 38-year-old, with the rich tones of a theatrically-trained actor. "That was one of the best bits of preparation I could have had for playing Dr King."

Former Spooks actor Oyelowo - who has received critical acclaim (although, controversially, no Oscar or Bafta nominations) for his portrayal of Dr King - also gained weight, shaved his hairline back and visited "where [King] was born, where he died, and everywhere in between" ahead of filming.

But the Oxford-born son of Nigerian parents (whose surname is pronounced 'O-yellow-oh'), took care not to turn his portrayal into a caricature.

"What people gravitate towards on the screen is a human being, not a statue. My job was to find the blood and guts of this man - the heroism but also the weaknesses, the foibles," he says.

Surprisingly, Selma, directed by Ava DuVernay and co-produced by Oprah Winfrey (who also makes an appearance on screen), is the first feature film to focus on Dr King, who was assassinated in 1968 aged 39.

It follows the preacher and activist's three-month campaign in Selma, Alabama, in 1965, to persuade President Lyndon B Johnson (played by The Full Monty's Tom Wilkinson) to introduce the Voting Rights Act, protecting African-Americans' right to vote.

Racial discrimination in voting was rife in many places; in Selma, only 130 of its 15,000 black citizens were registered to vote.

The film also depicts the shocking and bloody march from Selma to Montgomery, when hundreds of peaceful protesters were attacked by state troopers and police, and the public outcry which followed.

Oyelowo, who also appeared alongside Daniel Day-Lewis in Steven Spielberg's Lincoln in 2012, and Winfrey in 2013's The Butler, was struck by how long the battle to vote has been waged.

"There's a scene in Lincoln where I say the exact same thing to Abraham Lincoln as I say to LBJ in Selma," he notes. "In January 1865, my character [in Lincoln] is asking if we will be able to vote, and exactly 100 years later, I am still asking that same thing."

More than 50 years since the famous 'I Have A Dream' speech, calling for racial equality, what does the actor think Dr King would make of today's America?

"His dream hasn't been achieved, but elements of it have," says Oyelowo, who joined his co-stars at a recent red carpet event wearing 'I Can't Breathe' T-shirts, a reference to the last words spoken by Eric Garner, the black man who died in New York as he was arrested and reportedly put in a 'chokehold' for selling untaxed cigarettes last year, sparking mass outrage.

"I think he'd be elated at the fact that America currently has a black president, and I think he'd be happy at the fact that Oprah Winfrey is in the world, which is one of the reasons this film got made. I think he'd be very proud of Ava DuVernay as an African-American woman being the one to direct the first film that's centred around him as the protagonist.

"But I think he would be disheartened at how for granted the vote is being taken by all people, but especially young people and a lot of African-American people. When you look at this film and this episode in history, this was a right that was fought for and bought in blood. He'd be despondent at that."

Oyelowo, now based in Los Angeles with his actress wife Jessica and their four children, adds: "I think he'd be heartened by the fact that in light of the racial tensions of late, in America and around the world, largely we're seeing peaceful protest. He was the greatest exponent of that, and I think it's part of his lasting legacy."

Much has been made of the fact the film was overlooked in this year's Bafta shortlist, and only earned two Oscar nods, for Best Picture and Best Original Song. In fact, this year's Academy Awards have been described as the "whitest" since 1998, with no non-white actors nominated.

While Oyelowo has admitted that the lack of Oscar nominations "bothers me", he says he's content that "the film is really resonating with audiences".

And he's "very, very proud" of his fellow Brits Eddie Redmayne and Benedict Cumberbatch for their nominations.

"I've seen Eddie in The Theory Of Everything and I think he's phenomenal in that role, I've also seen Benedict as Alan Turing [in The Imitation Game] and again, just a stupendous performance."

A committed Christian, Oyelowo's faith has helped him navigate the highs and lows of his profession.

"One of the dangers of being an actor is the fact that you don't really know you're good unless people tell you," he admits with a smile.

"That's a very dangerous thing to hitch your self-esteem to. For me, my faith and being a Christian is a bigger part of my life than being an actor... It helps me keep a balance in my life."

EXTRA TIME - FIVE MUST-WATCH PROTEST FILMS

:: Bloody Sunday (2002) - James Nesbitt and Tim Pigott-Smith star in Paul Greengrass' drama about the 1972 civil rights march in Derry, which turned to tragedy when soldiers opened fire on protesters.

:: The Dreamers (2003) - Set against the backdrop of the 1968 Paris student riots, this film follows a young US student (Michael Pitt) who befriends a French brother and sister (Louis Garrel and Eva Green).

:: Made In Dagenham (2010) - Recently turned into a West End musical, this film depicts the 1968 strike at a Ford car plant in Essex, when female workers took a stand for equal pay.

:: Pride (2014) - Matthew Warchus' heartwarming film recounts the story of the gay activists who supported the miners' strike during the summer of 1984. Imelda Staunton, Bill Nighy and Paddy Considine co-star.

:: Suffragette (2015) - Meryl Streep plays Emmeline Pankhurst in this upcoming drama about the British women's suffrage movement. Helena Bonham Carter and Carey Mulligan also appear.

:: Selma is in cinemas on Friday, February 6