Organise related checks and get ready for action (5,3,5)
I believe the answer is:
clear the decks
'get ready for action' is the definition.
(I've seen this in another clue)
'organise related checks' is the wordplay.
'organise' is an anagram indicator.
'related'+'checks'='relatedchecks'
'relatedchecks' with letters rearranged gives 'CLEAR THE DECKS'.
'and' acts as a link.
(Other definitions for clear the decks that I've seen before include "Remove obstacles to action" , "tidy up after game of rummy" , "Get shipshape - prepare for action" , "Prepare for action - these crackled (anag)" , "Prepare for something by dealing first with matters outstanding" .)