Veteran actor Brain Blessed tells Viv Hardwick about his dogged efforts to amuse all the family this Christmas with a charming tale about talking sheepdogs.

"Children these days are so discerning,'' Brian Blessed says. ''If they don't believe, they don't believe. You've got to tell a proper story - a beginning, a middle and an end. And it's got to be full of magic.''

When it comes to telling a good story, the veteran actor, 69, knows his stuff. He was perfectly placed to lend his famous vocal talents to Five's homegrown Christmas film, Mist: The Tale Of A Sheep-dog Puppy.

The family film recounts the coming of age of sheepdog Mist as she says goodbye to her siblings and starts on the path to working with sheep. Filmed with real animals, the film is an impressive feat of direction on the part of the team who made it.

''They had difficulties, but cheerful and humorous difficulties. You don't know whether you're going to pull it off or not with animals, but if you stop taking risks you start to lose,'' Blessed says. An animal lover himself - Blessed lives on an animal sanctuary in Windlesham in Surrey with his wife, actress Hildegarde Neil, and is also President of the Council for National Parks - the actor has filmed many a nature documentary.

But he jumped at the chance to get behind the camera and actually play an animal - in this case sheepdog Sir Gregory, Mist's grandfather and mentor who oversees her training as a sheepdog.

''I spend an awful lot of time with animals and it's amazing how you can put a camera on them and they enact stories,'' he says. ''Doing the sheepdog film, I just found them an amazing inspiration as well.

''They're wonderful dogs, their intelligence is astonishing. I saw one the other day walking around our sanctuary. She had seven sheep with her and they loved her, sat with her and gathered around her. Simply sensational.''

Mist is not, of course, Blessed's first foray into voice acting. His famously deep, often bellowing tones can be heard on many an advert, TV show and film. But, he says, voice acting is not as easy it might seem.

''I did Disney's Tarzan film and I was on that job for two years. It was about 30 sessions in the end. They kept refining it, refining the lines. I kept going backwards and forwards every six weeks while they rewrote the script.

''I had to make the character less villainous, more human, or bring out a certain line a bit more. I do a lot of voice-overs and you cultivate a technique for it, and a belief in what you're doing. You've got to make it believable.''

* Mist: The Tale Of A Sheepdog Puppy, Five, Christmas Day, 12.30pm.