Made-up address politician chasing promotion might give? (2,3)
I believe the answer is:
ad lib
'made-up address' is the definition.
(an improvised utterance or address)
I cannot understand how the rest of the clue works.
(Other definitions for ad lib that I've seen before include "As You Like It?" , "Perform without a script" , "Speak unprepared" , "Freely available" , "Made-up" .)