Ardingly College pupil Joshua Williams, 13, is in the running for the role of Eustace Scrubb in the epic production of The Voyage of the Dawn Treader, which would require him to relocate to Slovenia for six months next year.

Scrubb is the cousin of the Pevensie children from The Lion, The Witch and the Wardrobe. In the film, he will accompany King Caspian on a land and sea quest to find the seven lost lords of Narnia.

Joshua's mother Hilary said the whole experience was a bit surreal: "One minute, Josh was just a good all-rounder, working hard at school - now we face the prospect of him going abroad for up to six months and becomine an international star."

Joshua and his nine rivals will travel to London this month to take a screen test and meet director Michael Apted. If he wins the role, he will be put under an option to appear in the fourth Narnia film, The Silver Chair.

His drama teacher Clair Ballantyne, whose former pupil Julia Winter played Veruca Salt in Charlie and the Chocolate Factory, said Josh was a dynamic performer, who throws himself into his roles.

She added: " He has an intuitive understanding of what is required onstage and knows how to captivate an audience. This is an amazing opportunity for him."