British PM and his majesty live in dark times - this may brighten up the sky (8,6)
I believe the answer is:
northern lights
'british pm and his majesty' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
'live in dark times this may brighten up the sky' is the wordplay.
I cannot really understand how this works, but
'live' could be 'l' (electrical abbreviation) and 'l' is found within the answer.
'dark' could be 'night' (it's dark at nighttime) and 'night' is present in the leftover letters.
'up' could be 'north' (I've seen this in another clue) and 'north' is found in the answer.
The remaining letters 'ers' 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 northern lights that I've seen before include "overhead display" , "Celestial phenomenon" , "What flickers in the sky" , "Blackpool illuminations?" , "a must-see for Arctic cruisers?" .)