Lists of candidates (6)
I believe the answer is:
slates
'lists of candidates' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for slates that I've seen before include "Berates with roofing tiles" , "Strongly criticises the roof tiles" , "Criticises severely using roof coverings" , "Strongly criticise the roof tiles" , "Thin layers of rock for roofing" .)