For a special occasion, taking tea? I don't think so! (2,6)
I believe the answer is:
no chance
'for a special' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.
'occasion taking tea? i don't think so' is the wordplay.
I cannot really see how this works, but
'tea?' could be 'cha' (cha is a type of tea) and 'cha' is located in the answer.
'occasion' could be 'nonce' (I've seen this before) and 'nonce' is located in the remaining letters.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for no chance that I've seen before include "That will not happen/succeed" , "pessimistic forecast" , "Most unlikely!" , "Monopoly could be badly affected by this" , "That's definitely out" .)