The most common and most likely answer to this crossword clue is the 12 letter word BREADWINNERS
I've seen this crossword clue in The Daily Telegraph
B
R
E
A
D
W
I
N
N
E
R
S
More clues leading to the result BREADWINNERS
Buddy explains!
The straight part
We know that "Supporters of family life" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case supporters of family life = breadwinners.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 BREADWINNERS mean?
BREADWINNERS noun- The primary income-earner in a household.