The most common and most likely answer to this crossword clue is the 7 letter word MARXIST
M
A
R
X
I
S
T
More clues leading to the result MARXIST
- Red tram carrying half a dozen uphill
- Red Cross is in the market
- Commie figure in vehicle to the left?
- Fair, perhaps, to have teams in red
- Revolutionary character signifying love is seen in market-place
- Spoil vote? It’s unusual for a left-winger
- Communist type put six back in trading centre
- Spoil team having gutted smart left-winger
- Red Cross is located in trade centre
- Damage to be deposing leader based on class struggle?
Buddy explains!

The straight part
We know that "based on class struggle" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case based on class struggle = marxist.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.