Neither revolutionary supports independent press (4)
I believe the answer is:
iron
'press' is the definition.
(I know that press can be written as iron)
'neither revolutionary supports independent' is the wordplay.
'neither' becomes 'nor' (eg in the phrase 'neither do I').
'revolutionary' says the letters should be written backwards.
'supports' is a charade indicator (letters next to each other) (bottom letters provide a support for the top ones).
'independent' becomes 'i'.
'nor' back-to-front is 'ron'.
'ron' after 'i' is 'IRON'.
(Other definitions for iron that I've seen before include "Metallic chemical element" , "Main element in steel" , "Magnetic metallic element" , "Decrease" , "Hard metal" .)