Green’s Dictionary of Slang

a Trotskyite, used indiscriminately for any hard-left group in the UK.

1968		Manchester Guardian Weekly 30 May 5: It is now definite on the fact that it has no ‘Trots’ on the Council.
1976		P. Theroux Family Arsenal 190: We’re mainly Trots, but some are outright anarchists.
1989		T. Blacker Fixx 207: Bloody BBC Trots.
1999		Guardian Rev. 24 July 6: He was no long-haired hippy leftie, much less a clipped-voice Trot.
2006		I. Rankin Naming of the Dead (2007) 220: Thought you lot had your hands full with all the Trots and Chairman Maos.