Johnson's predecessor a fashionably-dressed person? Why not? (3,2,4)
I believe the answer is:
may as well
'why not?' is the definition.
(I've seen this before)
'johnson's predecessor a fashionably-dressed person?' is the wordplay.
I cannot really understand how this works, but
'a' is within the answer.
'person?' could be 'swell' (swell is a kind of person) and 'swell' is present in the answer.
The remaining letters 'mya' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for may as well that I've seen before include "No reason not to" , "for the whole of spring?" .)