The British filmmaker opted out of taking charge of the Fifty Shades of Grey sequel earlier this year (15), amid reports of creative differences with author E.L. James, but now she has signed on to switch subject matters with real-life political drama Chappaquiddick.

The movie focuses on the seven days following the fatal car accident the Massachusetts senator was involved in in 1969, when his political career was thrown off track by the death of his passenger Mary Jo Kopechne, a former campaign worker for Ted's assassinated older brother Robert F. Kennedy.

Ironically, the script, penned by Taylor Allen and Andrew Logan, was included on the newly-released 2015 Black List, which recognises the year's most-liked unproduced screenplays.

Casting for the project has yet to be announced, but production is due to begin in the spring (16), according to The Hollywood Reporter.

Ted Kennedy died from brain cancer in 2009, aged 77.

The political project is Sam's first since walking away from the Fifty Shades of Grey franchise in March (15).

"Directing Fifty Shades of Grey has been an intense and incredible journey for which I am hugely grateful," she explained at the time of her departure. "I have (studio) Universal to thank for that. I forged close and lasting relationships with the cast, producers and crew and most especially, with (stars) Dakota (Johnson) and Jamie (Dornan).

"While I will not be returning to direct the sequels, I wish nothing but success to whosoever takes on the exciting challenges of films two and three."

Glengarry Glen Ross director James Foley has since been hired as Sam's replacement and he will shoot both the second film, Fifty Shades Darker, and final movie, Fifty Shades Freed, back-to-back, with production starting next year (16).

Dakota and Jamie will both return for the sequels.