Ban on sailing vessels turning up and dropping off children is to remain after all (4,2)
I believe the answer is:
stay on
'remain after all' is the definition.
'stay on' can be an answer for 'remain' (synonyms). I am unsure of the 'after all' bit.
'ban on sailing vessels turning up and dropping off children' is the wordplay.
I cannot quite see how this works, but
'on' is within the answer.
The remaining letters 'stay' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'is to' acts as a link.
Can you help me to learn more?
(Other definitions for stay on that I've seen before include "Remain after others have left" , "Remain behind" , "stick" , "Remain after normal time" .)