Thailand's recently ousted former prime minister Phatthana Shinawatra resigned on Wednesday as head of the Pheu Thai party founded by her father, former prime minister Thaksin Shinawatra, in a move that political analysts said signaled the end of the Shinawatra family's political dynasty that has dominated Thailand for two decades.

The 39-year-old Phatthongtharam was removed from office by a court in August, less than a year after being charged with misconduct over a border dispute with Cambodia.

The Thaksin Shinawatra family has been a key rival to Thailand's military and royal elite for the past two decades. The elite have accused the Shinawatra family of populist politics of threatening traditional social structures.

But the Shinawatra family has faced a difficult legal and political phase in recent years. Thaksin, 76, is serving a prison sentence on corruption charges stemming from his own rule. This has added to the pressure on the family.

The Pheu Thai Party said in a statement on Wednesday that it had formally accepted Phatthongtharam's resignation. "My resignation will help the party to completely reform and ultimately we will be able to win re-election," she said in a statement. She pledged to remain an ordinary member of the party and "continue to work hard for our Thailand." Thaksin founded the Thai Rak Thai Party, the first branch of Pheu Thai, in the late 1990s. He was forced to live in exile for more than a decade after being ousted in a 2006 military coup. Patong is the third Shinawatra to become prime minister, after his father Thaksin and aunt Yingluck Shinawatra. She is considered the last member of the family to be actively involved in politics. Political analysts say her resignation signals the gradual waning influence of the Shinawatra family in Thai politics. However, some still believe the family's influence behind Pheu Thai remains strong.