BANGKOK >> Thailand’s main opposition party announced Sunday it was resigning from Parliament to protest what it called "the illegitimacy" of the government. The move deepens the country’s latest political crisis a day before new street demonstrations that many fear could turn violent.

Democrat Party spokesman Chavanond Intarakomalyasut told The Associated Press his party could not work in the legislature anymore because the body is "no longer accepted by the people."

The minority Democrats are closely aligned with anti-government protesters who in recent weeks have staged the country’s biggest rallies in years. The demonstrations are aimed at ousting Prime Minister Yingluck Shinawatra, whose democratically elected government came to power in a landslide vote in 2011 that observers said was free and fair.

The Democrats have not won an election since 1992, and some of their leaders appear to have given up on electoral politics because they cannot win. The protesters are demanding a non-elected people’s council lead the country instead.

Thailand has been plagued by political turmoil since Yingluck’s brother Thaksin Shinawatra, a former premier, was toppled in a 2006 military coup. At least five people have been killed and at least 289 injured since the latest unrest began last month.

Democrat leader and former premier Abhisit Vejjajiva told reporters the resignations were effective immediately.

He said Yingluck’s government has been "illegitimate" ever since her ruling party tried to ram through an amnesty bill that critics allege was mainly designed to bring back Thaksin from exile. Thaksin lives in Dubai to avoid a jail sentence for a corruption conviction he says was politically motivated.

"The solution to our current problems needs to start with the showing of responsibility," Abhisit said. "The prime minister has never showed any responsibility or conscience."

Abhisit also criticized Yingluck’s Pheu Thai party for trying to amend a clause in the constitution that would have transformed the Senate into a fully elected body. Currently about half its members are selected by a panel of judges and heads of independent state agencies. The Constitutional Court sharply scolded Yingluck’s party for the move.

Chavanond said the pullout would affect about 150 Democrat-held seats in the lower house of the 650-member bicameral assembly.