Raised objections to ashtray item (4)
I believe the answer is:
stub
'ashtray item' is the definition.
(I've seen this in another clue)
'raised objections' is the wordplay.
'raised' shows that the letters should be reversed in order (going up in a down clue).
'objections' becomes 'buts' (as in 'no ifs, no buts').
'buts' in reverse letter order is 'STUB'.
'to' acts as a link.
(Other definitions for stub that I've seen before include "Tooth remnant" , "evidence of smoking, for example" , "Broken-off end" , "Extinguish the cigarette on a counterfoil" , "Returned part of a ticket" .)