'Income', posh Tory leader admitted, 'is healthy' (8)
I believe the answer is:
salutary
'healthy' is the definition.
(thesaurus)
'income posh tory leader admitted' is the wordplay.
'income' becomes 'salary' (I've seen this before**).
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-u).
'tory leader' becomes 't' (I've seen this in other clues).
'admitted' indicates putting letters inside.
'u'+'t'='ut'
'salary' enclosing 'ut' is 'SALUTARY'.
'is' acts as a link.
(Other definitions for salutary that I've seen before include "Beneficial, bringing a timely warning" , "Good for one" , "Having beneficial or wholesome effect" , "Promoting good health" , "Containing or bringing a timely (health) warning" .)