Worker on strike shows restraint (8)
I believe the answer is:
handcuff
'restraint' is the definition.
(handcuff is a kind of restraint)
'worker on strike' is the wordplay.
'worker' becomes 'hand' (hand is a kind of worker).
'on' is a charade indicator (letters next to each other).
'strike' becomes 'cuff' (I've seen this before**).
'hand'+'cuff'='HANDCUFF'
'shows' acts as a link.
(Other definitions for handcuff that I've seen before include "Restrain (one arrested)" , "Put bracelets on" , "Manacle" , "Restraint" , "Shackle by the wrist" .)