Cover up man supporting strike action (6)
I believe the answer is:
swathe
'cover up man' is the definition.
'swathe' can be an answer for 'cover' (I've seen this before). I am not sure about the 'up man' bit.
'supporting strike action' is the wordplay.
'supporting' means one lot of letters go next to another (in a down clue, some letters go under others).
'strike' becomes 'swat'.
'action' becomes 'he' (I can't explain this - if you can you should give a lot more credence to this answer).
'swat' next to 'he' is 'SWATHE'.
Can you help me to learn more?
(Other definitions for swathe that I've seen before include "considerable cut" , "Wrap; bandage" , "Strip cut by a scythe" , "Broad strip (land)" , "Wrap in bandages - broad mown band" .)