Deadlock that is about MP and fool (7)
I believe the answer is:
impasse
'deadlock' is the definition.
(synonyms)
'that is about mp and fool' is the wordplay.
'that is' becomes 'i.e.' (synonyms).
'about' is an insertion indicator.
'and' means one lot of letters go next to another.
'fool' becomes 'ass' (both can mean a stupid person).
'mp'+'ass'='mpass'
'ie' enclosing 'mpass' is 'IMPASSE'.
(Other definitions for impasse that I've seen before include "failure to progress" , "Situation of deadlock" , "No progress is possible in this type of situation" , "Deadlock or stand-off" , "Lack of movement" .)