A politician was someone who held political office.
Councillor Valron was a Kaled politician who was having an affair with Scientist Shan, a member of the Scientific Elite, towards the end of the Thousand Year War between the Kaleds and the Thals on Skaro. (AUDIO: Davros, Corruption)
Congressman Brook was a 26th century Earth politician who favoured war against the Draconians. He spoke English with a pronounced American South accent. (TV: Frontier in Space)
Sir John Sudbury was a British politician. He was the head of C19 from the early 1970s (PROSE: The Eye of the Giant, The Scales of Injustice) to as late as 1989. (PROSE: Business Unusual)
Vladimir Kryuchkov was a prominent Soviet politician during the 1980s. He was considered a militant hardliner. (AUDIO: Protect and Survive)
In the early 21st century, the Master adopted the identity of politician Harold Saxon and became Prime Minister of the United Kingdom. (TV: The Sound of Drums)