Paradise for PM once (4)
I believe the answer is:
eden
I believe this is a double definition.
'paradise' is the first definition.
(Garden of Eden)
'pm once' is the second definition.
(Anthony Eden, UK prime minister 1955-1957)
'for' acts as a link.
(Other definitions for eden that I've seen before include "Genesis garden" , "The first habitat" , "5,27 [PRIME MINISTER]" , "Leading 11 [CONSERVATIVE]" , "Someone once seen in Number Ten's" .)