Working with volunteers, parking freely available (2,3)
I believe the answer is:
on tap
'freely available' is the definition.
(I've seen this before)
'working with volunteers parking' is the wordplay.
'working' becomes 'on'.
'with' means one lot of letters go next to another.
'volunteers' becomes 'ta' (abbreviation for Territorial Army).
'parking' becomes 'p'.
'on'+'ta'+'p'='ON TAP'
(Other definitions for on tap that I've seen before include "Ready for immediate use" , "Always available" , "Ready to be drawn off, like beer" , "Where you may see H or C" , "Of liquid gas, ready to be drawn off" .)