The remake features a screenplay, by Academy Award winner Emma Thompson, that will incorporate the preface and sequel to Pygmalion, the George Bernard Shaw play on which the musical is based.

The film is in development at Sony, pending legal issues over the rights to the musical.

Firth appeared on the London stage in Another Country, The Caretaker and Three Days of Rain, among other plays. In addition to "The King's Speech," his screen credits include "A Single Man" (Oscar nomination), "Easy Virtue," "Mamma Mia!," "The Importance of Being Earnest," "Bridget Jones' Diary" (and its sequel), "Shakespeare in Love," the film version of "Another Country" and the 1995 BBC-TV miniseries of "Pride and Prejudice."

Mulligan appeared in The Seagull on Broadway (Drama Desk nomination) and in London, with additional London stage credits including Forty Winks, The Hypochondriac and Tower Lock Dreams. An Oscar nominee for "An Education," her other film credits include "Wall Street: Money Never Sleeps," "Brothers," "Public Enemies," the 2008 film of "Pride and Prejudice" and the BBC-TV miniseries "Bleak House."

My Fair Lady premiered on Broadway in 1956, starring Rex Harrison and Julie Andrews as English dialectitian Higgins and Eliza, the Cockney flower girl whom he bets he can transform into a lady.  The original film, released in 1964, starred Harrison and Audrey Hepburn.  The Broadway show won the 1957 Tony Award for Best Musical, and the film received the 1964 Oscar for Best Picture.  Harrison received Tony and Academy Awards for his performance.