Impersonating Lacus
Meer Campbell has a voice that sounds very similar to her idol's, Lacus Clyne. Reflecting this, both Meer Campbell and Lacus Clyne are voiced by Rie Tanaka[1] in the Japanese version and by Chantal Strand[2] in the English dub. Jillian Michaels provides the English singing voice of both as well.
Meer is contacted by Chairman Gilbert Durandal, who asks her to pose as Lacus. After she accepts the job, Meer's face is surgically altered to look identical to Lacus; however, she does wear a different shaped hairclip. Meer also takes Lacus' image as a pop star further: singing more upbeat versions of her songs, more dancing, more revealing clothing, etc.
Since Lacus has greater political influence than he does, Durandal uses Meer to gain support for his policies. Meer believes in Durandal's ideals, furthers his agenda by impersonating Lacus. Meer believes that by impersonating Lacus, she will be loved by everyone.
While few people can tell the difference between Meer and Lacus, Athrun Zala, Kira Yamato, and most of the other major characters in the Three Ships Alliance can tell she is not the real Lacus, especially since Lacus has been living with most of the senior members of the Three Ships Alliance in Orb, and later onboard the Archangel. In The Edge (a manga series depicting Athrun's side of the story), Gilbert Durandal acknowledges to Athrun that Meer is an impostor.
Meer is flirty and tends to be very excitable, especially in Athrun's presence. When she first meets Athrun, she introduces herself as Meer Campbell, and admits she is not Lacus Clyne. Throughout the series, Meer attempts to get closer to Athrun, though Athrun never encourages her and tells her that the real Lacus would not do any of the things which she does. When he defects, Athrun attempts to convince her to escape Gibraltar with him, she refuses, claiming that she is Lacus and that she prefers to be Lacus.
Hiding
Meer's imposture is revealed to the general public by Lacus after the Battle of Onogoro, when the real Lacus interrupted Meer's TV news broadcast. Following this, Durandal sends Meer, along with her bodyguard Sarah into hiding at the lunar city of Copernicus. Ironically, the Archangel, after being assigned to Orb's 2nd Space Fleet, also lands on Copernicus with Lacus Clyne in tow. Sarah informs Meer of the Archangel's presence and tells her that the other one may be with them. Sarah then suggests that Meer (whom she addresses as Lacus) do something about it, and Meer accepts.
As Kira, Athrun, Lacus, and Meyrin Hawke go shopping, Meer's red Haro gives a note to Lacus saying that Meer is going to be killed (or as the letter says "I'm going to killed! -Meer"). Athrun and Meyrin say they believe that it is a trap, but Lacus decides to go anyway, since Meer asked for Lacus' help. The other three accompany Lacus to meet Meer.
Later events
Meer meets the others in an empty amphitheater surrounded by armed men waiting in ambush. She is surprised to see Athrun, whom she thought had died after he was branded a traitor. Meer clings to the belief she is Lacus Clyne as the real Lacus tries to calm her down, telling Meer she is her own person with her own dreams, even if she looks and sounds like Lacus now. Desperate, Meer threatens to shoot Lacus but is stopped by Athrun, who shoots the gun out of her hands.
Sarah, who is lying in wait, tries to shoot Lacus, but Kira's mechanical bird Torii (Birdy in the dubbed version) alerts Athrun to the threat. Gunfire ensues, as Athrun takes down most of the armed men, and Sarah is seriously injured when a grenade she throws is deflected back at her by Kira and Meyrin.
Mu La Flaga arrives in the ORB-01 Akatsuki after the firefight to evacuate them all. Kira asks Meer to go with them, and she accepts. However, Sarah fires one more shot at Lacus; Meer tries to alert Lacus but is hit by the bullet while running towards her, while Athrun and Kira shoot and kill Sarah.
Meer gives Lacus a picture of herself before her cosmetic surgery, and she dies in Lacus' arms. Athrun carries Meer's body to the Archangel, where a funeral service is held for her. Lacus and the others read Meer's personal diary about her life (with her voice-over again not reflecting what is writen).
