A new face: Sir Keir and State both on the up (6)
I believe the answer is:
revamp
'a new face' is the definition.
(new version of something)
'sir keir and state both on the up' is the wordplay.
I cannot quite understand how this works, but
'state' could be 'va' and 'va' is found within the answer.
'on' could be 're' (regarding) and 're' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for revamp that I've seen before include "Give new appearance to" , "get in better shape" , "Refurbish" , "Patch up or renovate" , "overhaul" .)