Government representatives backed me by detaining fool (7)
I believe the answer is:
embassy
'government representatives' is the definition.
'backed me by detaining fool' is the wordplay.
'backed' says the letters should be written backwards.
'detaining' indicates putting letters inside.
'fool' becomes 'ass' (ass is a kind of fool**).
'me' written backwards gives 'em'.
'by' going around 'ass' is 'bassy'.
'em'+'bassy'='EMBASSY'
(Other definitions for embassy that I've seen before include "foreign mission abroad" , "Foreign Office" , "diplomatic venue" , "Office of an ambassador" , "Diplomatic mission" .)