Put out left-leaning workers’ organisation: it goes against the grain (8)
I believe the answer is:
crosscut
'it goes against the grain' is the definition.
(a cut against the grain of wood)
'put out left-leaning workers' organisation' is the wordplay.
'put out' becomes 'cross' (I've seen this before).
'left-leaning' is a reversal indicator (letters written right to left).
'workers' organisation' becomes 'TUC' (short for Trade Unions Congress).
'tuc' reversed gives 'cut'.
'cross'+'cut'='CROSSCUT'
(Other definitions for crosscut that I've seen before include "To alternate sequences when editing film" , "Sawn across the grain" , "It's going against the grain" .)