Leaflets now distributed round work all together (2,3,4,5)
I believe the answer is:
at one fell swoop
'all together' is the definition.
(I've seen this before)
'leaflets now distributed round work' is the wordplay.
'distributed' indicates an anagram.
'round' becomes 'o' (o is a circular letter).
'work' becomes 'op' (abbreviation for opus).
'leaflets'+'now'='leafletsnow'
'leafletsnow' anagrammed gives 'atonefellsw'.
'atonefellsw'+'o'+'op'='AT ONE FELL SWOOP'
(Other definitions for at one fell swoop that I've seen before include "46 [AT THE SAME TIME]?" , "all together" .)