While he was Director-General of the BBC, Birt was famously described by renowned playwright
Dennis Potter as a "croak-voiced Dalek". This comparison led to him being portrayed as Davros, the megalomaniac mad scientist and creator of the Daleks in a Christmas tape made by BBC staff. Reference was again made to this by actor
Tom Baker and former BBC director and producer
David Maloney on the DVD commentary for
Genesis of the Daleks: Part Five (1975).