The left slate has won 23 of the 48 places on the executive of Amicus, the union formed by merging AEEU and MSF.
The new executive took office on 1 January. According to Amicus insiders, most likely is the development of a 'centre-left' majority in the executive working closely with new general secretary Derek Simpson.
But it will be spurred on by a harder left minority within the executive and represents progress over the old right-wing regimes in AEEU and MSF.