Manage to miss ex-PM turning back to wave (5)
I believe the answer is:
evade
'manage to miss' is the definition.
'ex-pm turning back to wave' is the wordplay.
'ex-pm' becomes 'dave' (David Cameron).
'turning' is a reversal indicator.
'back to' suggests the final letters.
The last letter of 'wave' is 'e'.
'dave' written backwards gives 'evad'.
'evad'+'e'='EVADE'
(Other definitions for evade that I've seen before include "Slyly escape" , "Shun, escape" , "Dodge, elude" , "bypass" , "Dodge (taxes)" .)