Sheridan Moorkurk was the President of Earth. She didn't like the connection that the government had with the Conglomerate. She could hear the Laan. (AUDIO: The Sands of Life)
She was elected due to an unexpected surge in the protest vote against the Conglomerate. She came to see the Fourth Doctor and Romana I to find out information about the Laan. She didn't want the Conglomerate's CEO Cuthbert to wipe out the Laan. (AUDIO: War Against the Laan)
Cuthbert considered her to be a "sanctimonious bitch." (AUDIO: The Final Phase)