Left one working and helping (7)
I believe the answer is:
portion
'helping' is the definition.
(I know that helping can be written as portion)
'left one working' is the wordplay.
'left' becomes 'port' (left side of a ship - opposite of starboard).
'one' becomes 'i' (Roman numeral).
'working' becomes 'on' (on can mean working or activated).
'port'+'i'+'on'='PORTION'
'and' is the link.
(Other definitions for portion that I've seen before include "Share, helping" , "A lot of" , "Piece of a whole" , "Serving" , "Part - share" .)