The actress recently reteamed with her Black Swan director Darren Aronofsky for the drama Jackie, which will centre on the four days after her husband, President John F. Kennedy, was assassinated in 1963.

Now Sarsgaard is close to signing on as the late leader's brother, former Attorney General Robert, according to

The project, directed by Pablo Larrain, is expected to move into production at the end of the year (15), with Aronofsky serving as producer.

Sarsgaard will be in good company if he does portray Robert, aka Bobby Kennedy, onscreen - Martin Sheen, Jeffrey Donovan and Andrew MCCarthy have all previously tackled the role, while Barry Pepper took on the part in controversial 2011 TV mini-series The Kennedys, alongside Katie Holmes as Jackie and Greg Kinnear as John.