They will join Clive Carter (Mr. Salt), Jasna Ivir (Mrs. Gloop), Paul J. Medford (Mr. Beauregarde), Billy Boyle (Grandpa George), Roni Page (Grandma Josephine) and Myra Sands (Grandma Georgina), who will all remain in the cast.

New ensemble members include Dan Cooke, Divine Cresswell, Connor Dowling, Gemma Fuller, Robert Jones, Matthew Rowland, Rebecca Seale, Gregory Sims, Paulo Teixeira and Laura Tyrer. Further casting to be announced.

James originated the role of Seymour in the West End premiere of The Little Shop of Horrors, and played Thenardier on the 1988 Grammy Award-winning symphonic cast recording of Les Misérables. Other theatre credits include The Phantom of the Opera, Beauty and the Beast, Oliver!, She Loves Me (Olivier-nominated), Grand Hotel (all West End), Sweeney Todd (Olivier-nominated) and The Merchant of Venice, Rosencrantz and Guildenstern are Dead and A Funny Thing Happened on the Way to the Forum (all NT).

Gabrielle, who is currently in Two into One at the Menier Chocolate Factory, has been Olivier-nominated for her performance in Merrily We Roll Along that also originated at the Menier before transferring to the Pinter Theatre. She was also Olivier-nominated for Sweet Charity that transferred from the Menier to the Haymarket. Other credits include Oklahoma! (National, West End and Broadway, for which she was Olivier-nominated in London and Astaire Award-nominated on Broadway), Hello, Dolly! (Open Air Theatre, Regent's Park) and The 39 Steps (West End).

Dempsey was most recently seen in the West End in A Midsummer Night's Dream at the Noel Coward Theatre. Other theatre credits include the world tour of Propeller's A Midsummer Night's Dream and The Merchant of Venice and Victor/Victoria (Southwark Playhouse). Malpass has previously appeared at the Theatre Royal, Drury Lane in The Lord of the Rings. Other credits include Maria in The Sound of Music and Jerry Springer – the Opera.

To book tickets, contact the box office on 0844 858 8877 or visit www.CharlieandtheChocolateFactory.com.