Loud workmen I’d recast in radio play (5,4,4)
I believe the answer is:
under milk wood
Here is my best explanation:
'radio play' is the definition.
(I've seen this before)
'loud workmen id recast' is the subsidiary indication.
'recast' indicates anagramming the letters.
'loudworkmenid' with letters rearranged gives 'undermilkwood'.
'in' is the link.
(Other definitions for under milk wood that I've seen before include "Work by Dylan Thomas", "Welsh play", "Fail fully to exploit deal", "Radio play by Dylan Thomas", "radio play", "Dylan Thomas work", "Radio poem by Dylan Thomas" and "Play".)