Rebecca Ferguson to star in 'Florence Foster Jenkins'
The Pathe-financed pic follows the true story of the titular character (Streep), a wealthy woman in the early 20th century NYC high society who used her relationships and her fortune to gain traction as a singer.
Grant plays her butler and best friend, while Ferguson, 28, will play Grant's long-suffering wife, reported Deadline.
Ferguson is enjoying a roller-coaster year.
Having scored the female lead opposite Tom Cruise in "Mission: Impossible - Rogue Nation", she now moves straight into a prestige project opposite another screen icon in Streep.