factionist
/ˈfækʃənɪst/Definitions
1. noun
A person who is part of a faction, especially one that is opposing the official leadership or government.
“The factionist leader was secretly working with the opposition party to bring down the government.”
2. noun
A person who advocates for or supports a faction, especially one that is opposing the official leadership or government.
“The factionist movement gained momentum as more people began to support the cause.”