IT has been a busy year for Paul Brannigan.

Hot on the heels of his success in Ken Loach flick The Angels' Share, the Glasgow actor is soon to grace the big screen again in Hollywood sci-fi thriller Under The Skin, starring opposite Scarlett Johansson.

Then there is his role in musical Sunshine On Leith, a tale based on songs by The Proclaimers.

Closer to home Paul has won the nation's hearts as lovable rough diamond Gareth O'Connor in BBC soap River City.

Recent weeks have been fraught for his on-screen alter ego, with events due to reach their dramatic climax tomorrow.

As hardmen Billy Kennedy and Lenny Murdoch discover he has turned police informant, Gareth is faced with making the ultimate sacrifice to protect his girlfriend, Nicole, and her newborn baby, Grace, before exiting Shieldinch for good.

Shooting the powerful and heartbreaking scenes, proved testing for Paul.

"It has been pretty emotional filming the final episodes," he said, describing it as "challenging" and a "rollercoaster".

The 28-year-old tapped into a bank of raw emotions as he stepped into his character's shoes.

"There was a scene where I had to walk outside and cry," he said. "I started to think about my own son and, as sad as it sounds, you do need to think of bad thoughts to get to that place. I also tried to use different situations from my own past life.

"I can relate to the decision Gareth has to make. Growing up in the East End of Glasgow and being part of certain social circles, you do make sacrifices because it is what you believe in.

"If you are part of a gang culture or a close family unit, then you will pretty much do anything for them."

Growing up in Barrowfield, Paul's childhood was set against a background of gang violence and petty crime.

His parents were long-term drug addicts and, at 16, Paul was sentenced to almost four years in prison for discharging a firearm.

While he has never tried to hide his upbringing, the actor is not keen to keep picking over old ground.

"I thought the best thing was to be truthful," he said.

"It's part of who I am. I tell kids this story to try and inspire them to step away from that life.

"I thought if I could get the facts out first it would stop other people putting their bit in," he added.

"Even so, there has still been stories I have looked at it and thought: 'That's a load of rubbish'. But I just have to get on with it.

"It can be difficult every time you read a paper and the headline says: 'Paul Brannigan - both parents were heroin addicts".

"I'm over it. But I still have a brother who has to read that, as well as my mum and dad."

After his release from Polmont Young Offenders' Institution, Paul joined the Strathclyde Police Violence Reduction Unit as a volunteer football coach.

He was spotted by scriptwriter Paul Laverty and given the lead role of Robbie in The Angels' Share, for which he won a Bafta.

These days it is difficult for him to go anywhere without being asked for pictures and autographs.

"I was in Spain for 10 days and didn't get peace that entire time," said Paul. "It was strange, but really nice."

It is a situation unlikely to change any time soon, with two more big name films in the pipeline.

Paul's character in Under The Skin is seduced by Scarlett Johansson, who plays an alien preying upon hitchhikers in Scotland. It was filmed in Glasgow and Glencoe.

"That was one of the most challenging things I have ever done in terms of the physicality involved," he said.

"Let's just say I spent a lot of time underwater surrounded by oil and black gooey stuff. It was cold too."

He laughs when asked if his mates are jealous of him filming with one of the world's sexiest women.

"They call me a 'lucky wee you-know-what'," he said. "She was fantastic to work with and really gave me confidence."

Despite all his success, family remains his biggest priority. Paul and fiancee Sheree Coutts, 27, a youth worker, have a four-year-old son Leo, who has autism.

"The most important thing is giving my son something to aspire to," he said. "That's my biggest achievement."

Not that Leo is allowed to see everything his dad stars in, as Paul explains.

"He is always proud to see me on screen," said Paul. "I don't let him watch River City, but a few weeks ago he came downstairs and saw an aggressive scene that freaked him out. I tried to explain it to him, but he didn't understand and kept saying, 'You were very angry'.

"But after I took him down to the Dumbarton set to show him all the cameras and everything, he has been absolutely fine.

"When people come to the house, he always points to my Bafta and says, 'Look at my dad's trophy'. For me that is an amazing feeling. It is world's away from my past life."

l River City, tomorrow, BBC1, 8pm.