Prompt the news channels in time to change (9)
I believe the answer is:
immediate
'prompt' is the definition.
(I've seen this before)
'the news channels in time to change' is the wordplay.
'the news channels' becomes 'media' (I've seen this before).
'in' indicates putting letters inside.
'to change' indicates anagramming the letters.
'time' anagrammed gives 'imte'.
'media' going within 'imte' is 'IMMEDIATE'.
(Other definitions for immediate that I've seen before include "Instantaneous" , "Prompt,straightaway" , "Present" , "Involving no delay" , "Most urgent; current" .)