It's forbidden to make a scene in The Abbey - they might deem that sort of performance unlawful? (7,3)
I believe the answer is:
illegal act
'scene in the abbey they might deem that sort of performance unlawful?' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'it's forbidden to make a' is the wordplay.
I cannot really understand how this works, but
'forbidden' could be 'illegal' (I've seen this before) and 'illegal' is found in the answer.
'a' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
A single letter 'c' remains which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?