Party and drink, they infuriate one showing obstructionist attitude (3,2,3,6)
I believe the answer is:
dog in the manger
'one showing obstructionist attitude' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'party and drink they infuriate' is the wordplay.
I cannot really understand how this works, but
'party' could be 'do' (do is a kind of party) and 'do' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is present in the answer.
'drink' could be 'the' (I have seen 'French drink' mean 'the' so perhaps 'drink' could also mean 'the') and 'the' is found within the answer.
'infuriate' could be 'anger' (I've seen this in another clue) and 'anger' is located in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for dog in the manger that I've seen before include "Possessive person" , "possessive type?" , "Selfish person" , "error in farmyard?" , "Spoilsport" .)