PSOP appealed to a minority dissatisfied with both the SFIO and the French Communist Party ( PCF ) .
PSOP was a revolutionary socialist party , and had between 8,000 and 10,000 members .
Appealing to a minority dissatisfied with both the SFIO and the French Communist Party ( PCF ) , PSOP was a revolutionary socialist party , and had between 8,000 and 10,000 members .