Don't stop. There's a campaign in progress (5,2)
I believe the answer is:
drive on
'progress' is the definition.
I know nothing about this answer so I can't tell whether this works.
'don't stop there's a campaign' is the wordplay.
I cannot quite understand how this works, but
'there's' could be 'n' (I've seen this in other clues) and 'n' is present in the answer.
'campaign' could be 'drive' (synonyms) and 'drive' is found within the answer.
A single letter 'o' remains which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
'in' is the link.
Can you help me to learn more?
(Other definitions for drive on that I've seen before include "Advance by car" , "Don't stop estate possibly" .)