Co-writer, Bob Baker, explained the inspiration behind The Mutants. One of these inspirations was the withdrawal by the British Empire. The interviewees explained their view of imperialism with Terrance Dicks being pro-empire and Barry Letts holding the opposite view.
The theme of segregation was influenced by then-current racism in Africa. The word "Munts" was actually a derogatory term used by white South Africans for the black population. This resulted in its change to "Mutts".
The characters were examined, specifically Ky, Stubbs and Cotton. Bob Baker intended Cotton to be a cockney when he first wrote the script.