Deceptive advocacy of dire perils and sin (3,7)
I believe the answer is:
lip service
'deceptive advocacy' is the definition.
'dire perils and sin' is the wordplay.
'dire' indicates anagramming the letters.
'and' means one lot of letters go next to another.
'sin' becomes 'vice'.
'perils' anagrammed gives 'lipser'.
'lipser'+'vice'='LIP-SERVICE'
'of' acts as a link.
(Other definitions for lip service that I've seen before include "getting no proper acknowledgment" , "Insincere support" , "Insincere offer to assist" , "The hypocrisy" , "Insincere praise" .)