British label on pants giving one away in German's house (9)
I believe the answer is:
bundestag
'house' is the definition.
(I have seen 'German house' mean 'bundestag' so perhaps 'house' could also mean 'bundestag')
'british label on pants giving one away in german's' is the wordplay.
I cannot really see how this works, but
'british' could be 'b' (abbreviation e.g. in 'BBC') and 'b' is present in the answer.
'label' could be 'tag' (synonyms) and 'tag' is found in the answer.
'one' could be 'un' (northern English dialect form of 'one') and 'un' is found in the answer.
'german's' could be 'des' (abbreviation for Deutschland) and 'des' is located in the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for bundestag that I've seen before include "house in Germany" , "German parliament building" , "German diet" , "German house" .)