The most common and most likely answer to this crossword clue is the 5 plus 3 letter word POWER CUT
P
O
W
E
R
C
U
T
More clues leading to the result POWER CUT
- Command less authority, when without electricity?
- Sulk about gang turning up when it gets dark?
- Generation gap sees gang returning in sulk
- Energy being interrupted, might stop filming
- Daunting hairstyle is failure in the main
- Truce broken after prisoner of war gets reduced authority
- Superior group capsized, stuck in vessel — it could suggest an emergency
- Disruption of energy when core company staff rejected to break away
Buddy explains!

The straight part
We know that "failure in the main" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case failure in the main = power cut.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.