Mon Mothma is making a surprise appearance in Rogue One and Star Wars fans can barely contain their excitement

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Star Wars fans have hailed the return of rebel leader Mon Mothma in the trailer for the Star Wars anthology film Rogue One.

Although the casting has not officially been announced, fans have widely speculated that the actress is Genevieve O'Reilly - who played the political leader in 2005´s Star Wars prequel, Episode III - Revenge Of The Sith.

Lord Of The Rings actor Elijah Wood wrote on Twitter:

In fact, a lot of people shared his excitement...

Mon Mothma originally appeared in 1983´s Return Of The Jedi, when she was played by Caroline Blakiston.

Genevieve was cast to play a younger version of the character in Revenge Of The Sith, but her speaking part was cut.

Genevieve O'Reilly
Genevieve O'Reilly (Ian West/PA)

The trailer for Rogue One: A Star Wars Story gives Mon Mothma a central role as she sends young rebel Jyn Erso - played by The Theory Of Everything's Felicity Jones - on a mission to steal the plans for the Death Star, the planet-destroying weapon of the evil Empire.

Inspecting Jyn, she comments: "On your own from the age of 15, reckless, aggressive and undisciplined."

Felicity Jones stars in Rogue One: A Star Wars Story
Felicity Jones stars in Rogue One: A Star Wars Story (Lucasfilm/YouTube)

The film's heroine fires back: "This is a rebellion, isn't it? I rebel."

Mon Mothma then tells her: "A major weapons test is imminent. We need to know what it is and how to destroy it."

The movie, led by Godzilla and Monsters director Gareth Edwards, takes place between Episode III and Episode IV.

The new cast of Rogue One: A Star Wars Story
The new cast of Rogue One: A Star Wars Story (Lucasfilm/YouTube)

Following on from 2005 prequel movie Star Wars: Episode III - Revenge Of The Sith, it provides a back-story to the first scenes of 1997´s Star Wars: Episode IV - A New Hope, when Princess Leia is seen concealing the plans for the Death Star in the droid R2-D2 before she is captured by the Galactic Empire.

Rogue One is the first of three planned standalone spin-off films. Auditions are reportedly taking place for another of the anthology films, which tells the story of a young Han Solo.

Rogue One: A Star Wars Story features the old favourites
Rogue One features classic Star Wars creations (Lucasfilm/YouTube)

Rogue One was written by Gary Whitta and Chris Weitz, from an idea by long-time Star Wars visual effects supervisor John Knoll.

The movie also stars Mads Mikkelsen, Forest Whitaker, Ben Mendelsohn, Diego Luna and Riz Ahmed.

The trailer features classic Star Wars creations including AT-ATs and stormtroopers, as well as the Death Star and the Imperial Star Destroyer.

Rogue One: A Star Wars Story is due for release on December 16.