The most common and most likely answer to this crossword clue is the 4 plus 2 plus 9 letter word STAY OF EXECUTION
I've seen this crossword clue in The Daily Telegraph
S
T
A
Y
O
F
E
X
E
C
U
T
I
O
N
More clues leading to the result STAY OF EXECUTION
Buddy explains!
The straight part
We know that "Situation when hanging’s left hanging" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case situation when hanging’s left hanging = stay of execution.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.