John Lennon recalled, in a 1980 interview with Playboy magazine: "I remember the day he [Harrison] called to ask for help on 'Taxman', one of his first songs.
The backing vocals' references to "Mr Wilson" and "Mr Heath", suggested by Lennon, refer respectively to Harold Wilson and Edward Heath; the former was the leader of the Labour Party and the latter the leader of the Conservative Party, the two largest parties in British politics.