No has been Oscar-nominated and looks at the referendum and ad campaign that helped force General Pinochet out of office.
Gael has worked with Amnesty before on The Invisibles; four films which charted the dangerous journey across Mexico for migrants who are kidnapped, raped and sometimes murdered as they aim for America.
You can submit your questions for Gael by leaving them as a comment or asking them via Twitter using #AskGael Questions are also being accepted for Eugenio Garcia, one of the two advertising executives who created Chile’s ‘No’ campaign who Gael’s character in the movie is partly based on.
The chat will take place for 45 minutes from 3.45pm on Thursday. For more details head over to Facebook