Thirteen-year-old Ellis used to struggle to stand up and say his name in public.

“He was so trapped in his own fear,” says Monica Savic-Jabrow, a qualified barrister who took on the role of mentoring Ellis. “He told me he felt like a lowlife. That’s a very, very powerful word for a young man to use.”

Just 15 weeks later, however, Ellis is standing up in public and taking down his fellow debaters with quick and clever asides.

Ellis’ transformation plays a key part in the first episode of a new eight-part documentary series, to be aired on Sky 1 this evening. Kings and Queens of Speech, produced by the makers of Educating Yorkshire, follows pupils from six inner-city schools as they overcome their inner introverts and learn to debate.

In the first episode, Ms Savic-Jabrow acts as mentor to Ellis and Rhys, two pupils at the Mosslands School on the Wirral.

“They were a couple of children who couldn’t say their own names,” Ms Savic-Jabrow says. “They stuttered and they fumbled and they didn’t have that self-belief that anyone would listen to what they had to say.

“We’re not taught confidence in school. It isn’t on the curriculum. People argue that it should be - it arms a child with skills they will use for the rest of their lives.”

Fourteen-year-old Rhys agrees. “In class, I never used to ask for help,” he says. “I always used to be quiet and let things drift off and happen. Now I’m not afraid to ask for help.

“And I never used to tell my mum about things happening at school. Now I do. It’s created better relationships, at home and at school.”

This, says the programme’s executive producer, Sam Grace, is exactly the reason why he wanted to make the series. “Everyone remembers the terror of standing up in front of their school or class,” he adds. “This is not a series about debating or public speaking. It’s about young people finding the inner confidence to overcome a fear that we can all identify with.”

And, for that reason, Adrian Whiteley, Mosslands headteacher, had few qualms about allowing the cameras into his school. “It wasn’t 90 cameras in every classroom,” he says. “This was two cameras, following a few children around. And they didn’t want to tell any stories about underachievement. They wanted to tell good-news stories.”

And debating is not beneficial only for pupils like Ellis, who are afraid to speak in public. “It’s easy to say that some pupils shine, and some pupils lack confidence,” he says. “But, actually, the ones who make lots of noise are probably just as lacking in confidence as those who are afraid to say anything.”

The first six episodes of the programme each focus on individual schools, and the challenges faced by their pupils. In episode seven, the teenagers progress to a debating tournament, held at the Oxford Union. The finalists win the chance to compete in the country’s most famous debating chamber: the Houses of Parliament.

The debating lessons were run by mentors from Debate Mate, a charity that helps disadvantaged pupils to develop their confidence and speaking skills.

“There’s a whole pile of stuff that increases confidence: programmes that teach dance, drama, juggling,” says Margaret McCabe, founder of Debate Mate.  “But to go straight into the classroom and have an effect there - there’s nothing else that teaches confidence like that.”

“It isn’t just about who wins the trophy,” adds Ms Savic-Jabrow. “It’s about the journey, the development of the child. It’s about realising their potential.

“Seeing Ellis transform from a shy child to a confident public speaker - it’s humbling. It’s extremely good for the soul. It’s a feeling second to none.”

Kings and Queens of Speech begins tonight, at 8pm on Sky 1.