LONDON— It’s a storm in a Stormtrooper’s helmet.

Lawyers for George Lucas’ Lucasfilm Ltd. and a British prop designer faced off in London’s High Court Tuesday over rights to the molded white Stormtrooper uniforms from the “Star Wars” films.

Standing alongside the bewigged, black-robed lawyers in court was the object of their dispute—a 6-foot tall, helmeted warrior of the evil Galactic Empire. Lucasfilm attorney Michael Bloch called the menacing figure “one of the most iconic images in modern culture.”

Lucasfilm claims violation of copyright and trademarks by prop designer Andrew Ainsworth, who sculpted the Stormtrooper helmets for the first “Star Wars” movie in 1977. London-based Ainsworth sells replicas of the helmets and armor, which he says are made from the original molds, on his Web site.

Lucasfilm won a $20 million judgment against Ainsworth in a California court in 2006, and is seeking to have it enforced in Britain.

Ainsworth is countersuing, claiming the copyright rests with him and seeking a share of merchandising revenue from the six “Star Wars” films, which his lawyers estimate at $24 billion.

Lucasfilm and its lawyers claim the design of the Stormtroopers was created by Lucas and his artistic team, and was already in place by the time Ainsworth was hired to create the helmets.