Drama created by Labour’s leader blocking workers’ reward (4)

I believe the answer is:
play
'drama' is the definition.
(synonyms)
'labour's leader blocking workers' reward' is the wordplay.
'labour's leader' becomes 'l'.
'blocking' means one lot of letters goes inside another (block can mean to plug a gap in something).
'workers' reward' becomes 'pay' (I've seen this in another clue. I am not sure about the 'workers'' bit.).
'l' placed within 'pay' is 'PLAY'.
'created by' acts as a link.
Can you help me to learn more?
(Other definitions for play that I've seen before include "Uncle's premises" , "Theatre performance" , "Dramatic work" , "Slack - performance" , "stage production" .)