The most common and most likely answer to this crossword clue is the 7 letter word UMPIRES
I've seen this crossword clue in The Guardian
U
M
P
I
R
E
S
More clues leading to the result UMPIRES
- Officials at Lord's super - I'm bowled over!
- Unionist politician’s anger with southern judges
- Prime us acting for those standing in the middle
- Judges appointed by Trump I respect
- Judges and Unionist lawmakers full of anger
- Politician has anger when restricted by American law-enforcers
- They throw up their arms when a certain line is crossed by hookers
- Super, Mumbai Indians managed two additional men in the field
- Politician with anger restricted by American judges
- Judges in America tackling politician's rage
Buddy explains!

The straight part
We know that "those standing in the middle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case those standing in the middle = umpires.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.
What does UMPIRES mean?
UMPIRES noun- The official who presides over a tennis game sat on a high chair.
- One of the two white-coated officials who preside over a cricket match.
- One of usually 4 officials who preside over a baseball game.
- The official who stands behind the line on the defensive side.
- A match official on the ground deciding and enforcing the rules during play. As of 2007 the Australian Football League uses 3, or in the past 2 or just 1. The other officials, the goal umpires and boundary umpires, are normally not called just umpires alone.
- A person who arbitrates between contending parties.
- The official who presides over a curling game.