LONDON - A musical version of childhood classic "Matilda" opened the London Film Festival on Wednesday, with actors Emma Thompson and Lashana Lynch the first of many stars expected to walk the event's red carpets over the next 12 days.

The movie, called "Roald Dahl’s Matilda the Musical", is an adaptation of the London West End and Broadway stage show based on Roald Dahl's 1988 book about a young girl who discovers she has a special power while dealing with cruel parents and nasty headmistress Miss Trunchbull.

"No Time to Die" actress Lynch swaps her 007 action stunts for a softer role as Matilda's kind teacher Miss Honey.

"This is a really good opportunity for me to flex a muscle I haven't in a long time," Lynch told Reuters.

"I sang before I acted and singing and music is really important to me. It moves me every single time and I'm just grateful that this 'Matilda' is a musical." Oscar winner Thompson plays Miss Trunchbull in the film, directed by Matthew Warchus, who also developed and directed the theatre show. "(It was) the most physically challenging thing I've ever done because it was so physical and also Matthew wanted her to be utterly authentic so it was hard because she's sort of such a monster," Thompson said.

"But we had such fun with the children and we would get on set and have these huge hug fests and Matthew would keep screaming 'Will you please stop hugging the children? They're supposed to hate you' and I said 'But they all think I'm Nanny McPhee," she added, referencing a past character she played.

This year's festival includes more than 160 feature films and screen talks with actress Jennifer Lawrence and director Alejandro G. Iñárritu among a line-up of big names looking back on their careers.

The programme includes red carpet events for Oscar winning-director Sam Mendes' "Empire of Light", Timothee Chalamet's portrayal of a cannibal on the run in "Bones and All" and Daniel Craig's second outing as detective Benoit Blanc in "Glass Onion: A Knives Out Mystery", which will close the festival on Oct. 16.

(Reporting by Sarah Mills; Additional reporting by Marie-Louise Gumuchian; Writing by Marie-Louise Gumuchian; editing by Diane Craft)