Representative put in new suite, as an incentive (7)
I believe the answer is:
impetus
'an incentive' is the definition.
(thesaurus)
'representative put in new suite' is the wordplay.
'representative' becomes 'mp'.
'put in' means one lot of letters goes inside another.
'new' is an anagram indicator.
'suite' is an anagram of 'ietus'.
'mp' inserted into 'ietus' is 'IMPETUS'.
'as' acts as a link.
(Other definitions for impetus that I've seen before include "Catalyst" , "Imputes to force with which a body moves" , "Momentum, stimulus" , "Incentive, stimulus" , "Thrust" .)