Refusal to work in lead (6)
I believe the answer is:
denial
'refusal' is the definition.
(I've seen this before)
'work in lead' is the wordplay.
'work' indicates anagramming the letters.
'in'+'lead'='inlead'
'inlead' anagrammed gives 'DENIAL'.
'to' acts as a link.
(Other definitions for denial that I've seen before include "Refusal to accept an unpalatable truth" , "Refusal, abnegation" , "Refusal to believe an unacceptable truth" , "Saying it isn't so" , "Negation" .)