Not in power, party men will be not in the house (7)
I believe the answer is:
outdoor
'not in the house' is the definition.
'not in power party men' is the wordplay.
'not in power' becomes 'out' (as in a political party out of government).
'party' becomes 'do' (do is a kind of party).
'men' becomes 'or' (I've seen this in other clues).
'out'+'do'+'or'='OUTDOOR'
'will be' acts as a link.
(Other definitions for outdoor that I've seen before include "Alfresco - sort of pursuits" , "not under cover" , "Not inside" , "External" , "Taking place in the open air" .)