Very old article by Conservative that is not without heart (7)
I believe the answer is:
ancient
'very old' is the definition.
(I've seen this before)
'article by conservative that is not without heart' is the wordplay.
'article' becomes 'an' (indefinite article).
'by' says to put letters next to each other.
'conservative' becomes 'c' (abbreviation commonly used in UK politics).
'that is' becomes 'ie' (synonyms).
'without heart' means to remove the middle letters.
'not' with its centre removed is 'nt'.
'an'+'c'+'ie'+'nt'='ANCIENT'
(Other definitions for ancient that I've seen before include "Veteran" , "of long standing" , "very old boy?" , "Bygone" , "over the hill" .)