Definition of "Trot"

Loyal to a tee, he is still at a loss to understand the failure of the Frank Dobson candidacy in the London mayoral contest, and abandoned constituency meetings after a couple of events because they were "too dominated by Trots".

2001 October 3, Matthew Tempest, “New Labour's power-dressed future”, in The Guardian‎

We believed that the Trots represented a mad, extreme form of Labour that was never going to do anything for anybody, yet we felt strongly that nothing would be achieved by jumping ship and defecting to the SDP.

2008, Cherie Blair, Speaking for Myself: My Life from Liverpool to Downing Street