Thailand's main opposition party on Monday nominated the sister of ousted Prime Minister Thaksin Shinawatra as its candidate for the top post in upcoming elections, a decision likely to inflame tensions in the country's highly polarized politics.

Yingluck Shinawatra, 43, has little political experience and is seen as a stand-in for Thaksin. She would likely become Thailand's first female prime minister if the opposition Pheu Thai Party wins the July 3 polls, which are expected to be close.

The ruling Democrat Party on Monday also named its candidate for the premiership, incumbent Prime Minister Abhisit Vejjajiva, according to party spokesman Buranaj Smutharaks.

Thailand has been gripped by political unrest since Thaksin's ouster by a military coup in 2006 after accusations of corruption and disrespect for the monarchy. He fled Thailand to escape a prison sentence and is barred from running for office, but remains highly popular among voters in the countryside.

"I am ready and confident" to run for the premiership, Yingluck told a news conference. "I would like to see reconciliation in the nation. I would use my being a woman to achieve that."

Last year, Thaksin's supporters, the "Red Shirts," held two months of anti-government protests in the capital that deteriorated into violence, leaving at least 91 people dead and 1,400 wounded. They demanded that Abhisit call early elections.

Yingluck has spent most of her career working for companies linked to the Shinawatra family. Thaksin, one of Thailand's richest men, made his fortune in telecommunications.

Thaksin has a history of using family members in politics. While prime minister in 2003, he appointed his cousin Chaisit Shinawatra to serve in the influential post of army commander.

In 2008, he maneuvered to have his brother-in-law Somchai Wongsawat become prime minister. Somchai was forced out of office by a court ruling and was succeeded after a brief caretaker administration by Abhisit, whose critics charge he came to power with the connivance of the military.

Thaksin, in an interview published Monday in the Post Today newspaper, predicted that Pheu Thai would win the most seats in the lower of house of Parliament, but that no party would win a majority, forcing the formation of a coalition government.

"If Pheu Thai wins the elections, it will not seek any revenge," Thaksin said. He said he expected the party to announce a national reconciliation plan during the campaign. Abhisit's government has touted its own reconciliation policies, but the country remains deeply divided.

Yingluck said it was too early to talk about bringing Thaksin back to Thailand, but that the coup that ousted her brother played a part in drawing her into politics.

"After five years, people still miss my brother and think about his policies," Yingluck said.