By Neil Smith BBC News entertainment reporter

Strong based his portrayal of Harry Starks on real-life East End villains

The 41-year-old Londoner played the lead role in the acclaimed adaptation of Jake Arnott's best-selling novel.

As Harry Starks, the gay East End gangster who dreams of entering high society, Strong gave a performance dripping with menace that was also tinged with pathos.

But Strong faces stiff competition in the best actor category from Rhys Ifans, Michael Sheen and newcomer Benedict Cumberbatch.

Ifans is up for his role in Not Only But Always, in which he played Peter Cook to Aidan McArdle's Dudley Moore, while Sheen is up for Dirty Filthy Love - about a man whose life is affected by Obsessive Compulsive Disorder and Tourette's Syndrome.

Cumberbatch is nominated for his portrayal of Professor Stephen Hawking in the BBC drama Hawking, which charted the scientist's early years as a PhD student at Cambridge University.

Self-deprecating

Strong's nomination - his first Bafta nod - follows years of sterling work in such TV dramas as Our Friends In The North, Prime Suspect, Henry VIII and Births, Marriages And Deaths.

Ask him to rate his chances on Sunday, however, and you get a modest and self-deprecating response.

Strong (second right) was one of the stars of Our Friends In The North

"I'd be surprised if I win to tell you the truth," he says.

"It's nice that the show gets recognition more than anything else. We're all very proud of it."

And he admits to being gratified by the reaction the drama received from audiences and critics alike.

"My peers have congratulated me while the critics have given it the nod, which I value very highly," he says.

"And a lot of people who don't know me very well think I'm terrifying and probably not to be trusted.

"No-one's told me they haven't liked it, at least not to my face," he adds.

"I don't know - maybe they were worried they'd get a hot poker in the eye."

Strong refers to the torture method favoured by his Long Firm character Starks, a man he describes as "in the gutter reaching for the stars".

'Repellent'

"A lot of gangster films show you what a gangster does," he says. "What was good about this programme was that it showed you what he wanted to become.

"It made a quite repellent character seem attractive and interesting."

Strong will star in Roman Polankski's upcoming version of Oliver Twist

The actor had made a good living recently out of repellent characters.

He plays Bill Sykes' henchman in Roman Polanski's upcoming version of Oliver Twist and a short-sighted assassin in Guy Ritchie's new film, Revolver.

Strong will also be seen alongside George Clooney and Matt Damon in Syriana, a new thriller from the writer of Oscar-winning drugs drama Traffic.

"It's a very brave film about America's involvement in the Middle East," he says. "I play one of Clooney's CIA agents, a third-generation Lebanese American who turns on him."

Right now, however, Mark has other things on his mind.

"I've taken some time off to be at home with my good lady and the baby (five-week-old Gabriel). I'm just being a proud dad at the moment."

And if he is lucky enough to win a Bafta on Sunday, do not expect him to have a speech prepared.