The live-action musical would reunite Blunt with director Rob Marshall, who helmed the aforementioned "Into the Woods."
Set 20 years after the events in the Andrews-Dick van Dyke classic, the film will be based on P.L. Travers' book series. The film will feature a new score composed by Hairspray Tony winners Marc Shaiman and Scott Wittman.
The story, according to the industry website, is "set in Depression-era London and revolves around a now-grown Michael Banks, who has children of his own. In tough times, big sister Jane returns and soon after, their beloved Mary Poppins comes back to help."
A production timetable has not been announced.