Using maximum power, everyone is on strike (3-3)
I believe the answer is:
all-out
'using maximum' is the definition.
'all-out' can be an answer for 'maximum' (I've seen this in another clue). I'm unsure of the 'using' bit.
'power everyone is on strike' is the wordplay.
I cannot quite understand how this works, but
'everyone' could be 'all' (all people) and 'all' is found within the answer.
'on strike' could be 'out' (I've seen this before) and 'out' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for all-out that I've seen before include "Using every effort - everybody exit" , "Whole-hearted (effort)" , "Using full strength or energy - nobody home?" , "Using every resource" , "Nobody home, at top speed" .)