The most common and most likely answer to this crossword clue is the 11 letter word BLUE-COLLAR
B
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More clues leading to the result BLUE-COLLAR
Buddy explains!

The straight part
We know that "hard working labourers" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hard working labourers = blue-collar.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 BLUE-COLLAR mean?
BLUE-COLLAR adjective- Working class; engaged or trained in essentially manual labor.
- Pertaining to the culture of blue-collar workers.