Thais vote on Sunday in a general election called by Prime Minister Thaksin Shinawatra to rout a campaign to oust him but likely to plunge the country into a constitutional mess, Reuters reported. Facing an opposition boycott, Thaksin turned the poll into a referendum by pledging to quit if his Thai Rak Thai (Thais Love Thais) party wins less than 50 percent of the ballots cast. That is unlikely to happen as rural Thais, who have enjoyed village handouts and cheap healthcare under five years of Thaksin rule, look set to give him another thumping majority. But the boycott means the result is almost sure to fall short of a constitutional requirement that all 500 parliamentary seats be filled for a new government to be formed. "The poll will produce a protracted deadlock for months. The final outcome is far from certain," political scientist Somjai Phagaphasvivat told Reuters. The crisis is already taking its toll on the economy, paralysing decision-making in business and sapping the Thai stock market, Southeast Asia's second worst performing bourse after Malaysia this year. The opposition and the People's Alliance for Democracy (PAD), an ad-hoc group bent on forcing Thaksin out, are urging voters to tick the "abstention" box on ballot papers as a vote against the Thai leader, whom they accuse of corruption and abuse of power. Thai Rak Thai candidates are running unopposed in 265 of 400 constituencies and as many as 50 could fail to win the minimum 20 percent of the vote they need to record victory in an uncontested seat, casting doubt on the validity of the overall result. Some 45 million Thais are eligible to vote when polls open at 8 a.m. (0100 GMT) and close 7 hours later. Preliminary results from the Election Commission (EC) are not due until early Monday.