Restrain worker going to strike (8)
I believe the answer is:
handcuff
'restrain' is the definition.
(I know that handcuff is a more specific form of fetter)
'worker going to strike' is the wordplay.
'worker' becomes 'hand' (hand is a kind of worker).
'going to' says to put letters next to each other.
'strike' becomes 'cuff' (both can mean to hit).
'hand'+'cuff'='HANDCUFF'
(Other definitions for handcuff that I've seen before include "Manacle" , "Restraint" , "Restrain (one arrested)" , "Restrict movement" , "Put bracelets on" .)