Doctor Who is fun because depending on the writer it swings between socialist, to milquetoast lib, to frothing British imperialist valorizing people like Churchill and Victoria.

Also the Doctor is sometimes a misogynist.

The least lib Doctors from what I've seen are the sixth, seventh, and twelfth. Sixth because he calls time lords imperialist at one point. Seventh because he helps a Soviet soldier use commie magic against vampires. Twelfth because he outright, explicitly says capitalism favors profit over people, in those exact words.

The most lib are the 3rd (willingly works for a British intelligence agency when he could just fly away to fartworld or something), 5th (for being an ardent pacifist so hard he gets Adric killed), 11th (loves Churchill), and 13th (oh my god I do not have time to type out how liberal she is)