Postponed? Oh, Lovely! (2,3)
I believe the answer is:
on ice
'postponed?' is the definition.
(I've seen this before)
'oh lovely' is the wordplay.
'oh' becomes 'o'.
'lovely' becomes 'nice' (I've seen this before).
'o'+'nice'='ON ICE'
(Other definitions for on ice that I've seen before include "In poky alone" , "Shelved" , "not to be furthered?" , "Postponed (fig.)" , "Chilling; suspended" .)