BANGKOK — Thailand's main opposition party petitioned a court Tuesday to annul last weekend's disrupted national election, launching a legal challenge that could prolong the deeply divided country's political paralysis. The Democrat Party's petition to the Constitutional Court also urges the dissolution of Prime Minister Yingluck Shinawatra's ruling party, which called Sunday's elections in a bid to defuse anti-government protests that started three months ago. Wiratana Kalayasiri, a former opposition lawmaker and head of the Democrat Party's legal team, said the petition argues the polls violated the constitution on several grounds, including that they were not completed in one day. Critics call the Democrats' argument counter-intuitive, saying the reason the election could not be finished in one day is because anti-government protesters backed by the party sabotaged the vote. The Democrat Party boycotted the election, and the protesters aligned with it forced the closure of hundreds of polling stations in Bangkok and the south, preventing millions of people from voting. As a result, a series of special elections are required to complete the balloting. Election results cannot be announced until all areas have successfully voted. “This election has violated the constitution on several counts, but mainly it was not a fair one,” Wiratana said. “The election was not held on the same day ... that is why we are seeking to nullify it.” Prompong Nopparit, spokesman for Yingluck's Pheu Thai party, said the Democrats “are initiating another front of attack to help the street protesters.” “They are the ones who did not even participate in the election. They are more likely the ones who are trying to overthrow democracy through unconstitutional means,” he said. Despite fears of violence, the voting proceeded peacefully in 90 percent of polling stations. The struggle to hold the balloting was part of a 3-month-old conflict that has split the country between supporters of Yingluck and opponents, who allege her government is too corrupt to rule, and that she is a puppet of her brother, ousted Prime Minister Thaksin Shinawatra. Thaksin, a billionaire businessman who is the most divisive figure in modern Thai history, fled into exile to avoid a corruption conviction after being deposed in a 2006 military coup. The demonstrators have occupied major intersections in Bangkok and forced government ministries to shut down and work elsewhere. The protesters are demanding the elected government be replaced by an unelected “people's council” to enact reforms ahead of new elections and remove the Shinawatra family's influence from politics. Yingluck has refused to step down, arguing she was elected by a large majority and is open to reform, but that such a council would be unconstitutional and undemocratic. — AP