Reese Witherspoon is reuniting with the man who cast her as the memorable high school president wannabe Tracy Flick in "Election": Alexander Payne.  The filmmaker's breakout picture was also Witherspoon's coming out party and after a decade, the duo are finally reuniting for the social satire "Downsizing."

Variety reports Witherspoon will join Sacha Baron Cohen and Paul Giamatti, who teamed with Payne for the acclaimed drama "Sidways," in the expected Fox Searchlight picture.  The original screenplay finds Giamatti paying a man strapped for cash who decides his life would be much easier if he undergoes a process to shrink himself.  Witherspoon plays a woman Giamatti meets on his incredible shrinking journey and Cohen would portrays a pint-sized foreigner.

Important to note: there is no deal in place for the three leads and no negotiations will occur until Payne finishes the screenplay which he is writing with longtime collaborator Jim Taylor.  And while Payne has a deal at Searchlight, the considerable special effects budget for "Downsizing" could kick it out of the specialty studio's realm. 

Jeff Wells of Hollywood-Elsewhere reported that Meryl Streep was also in line to star in the film, but she was conspicuously absent from the trade paper's report.

WItherspoon will hit theaters later this month as the voice of Ginormica in DreamWorks Animation's "Monsters vs. Aliens."  There are no current live action pictures on her slate.

Cohen is currently putting the finishing touches on the mockumentary "Bruno" which hits theaters this summer.

Giamatti recently completed "The Last Station" with James McAvoy and Helen Mirren.  He also received strong notices for his work in the Sundance Film Festival dramatic competition entry "Cold Souls."  But, the Oscar winner spent most of 2008 collecting every acting award imaginable for playing the second President of the United States in "John Adams."

More on this story as it develops on HitFix.

Stay up to date with the latest breaking news in the worlds of movies, TV and music by signing up for HitFix E-mail Alerts.

Don't miss out. Add HitFix to your iGoogle, My Yahoo or My MSN experience by clicking here.

Not part of the HitFix Nation yet? Take 90 seconds and sign up today.