Taxi I grab for senior ministers (7)
I believe the answer is:
cabinet
'senior ministers' is the definition.
(I've seen this before)
'taxi i grab' is the wordplay.
'taxi' becomes 'cab' ('cab' can be a synonym of 'taxi').
'grab' becomes 'net' (netting is a kind of grabbing).
'cab'+'i'+'net'='CABINET'
'for' acts as a link.
(Other definitions for cabinet that I've seen before include "some PMs dislike?" , "meeting at Number Ten" , "Collective noun for senior ministers" , "It may be shelved" , "Display cupboard - senior ministers" .)