Thailand voted on Sunday to approve a new constitution drawn up by the ruling junta, preliminary results showed, in a major victory for the army and a blow to the stuttering pro-democracy movement. Partial results released by the Election Commission late Sunday showed 62 percent of voters had approved the charter, with 90 percent of votes counted so far. Authorities estimated a subdued turnout at around 55 percent of Thailand's 50.2 million registered voters, after a poll run-up that saw independent campaigning and open debate barred. Sunday's referendum was the first time Thais have been able to go to the polls since army chief turned Prime Minister Prayut Chan-O-Cha toppled the elected government of Yingluck Shinawatra in 2014. The military says its new constitution will curb endemic political corruption and bring stability after the dizzying merry-go-round of recent years. Critics say it aims to neuter civilian politicians and tighten the grip of the military — and its allies in the royalist elite — over the country. The kingdom is split after a decade of political turmoil that has damaged growth, seen democracy shunted aside and left scores dead in rival street protests. The preliminary results starkly illustrate the kingdom's bitter geographic divide. Only the impoverished and rural northeast — a region that has voted in droves for successive governments turfed out by the army — and the deep south — hit by a Muslim insurgency — voted against the charter. Jatuporn Prompan, leader of the anti-junta Red Shirt movement, which is strongest in the northeast, hit out at the result. "I want to tell Prayut that your victory is nothing to be proud of as your opponents had no chance to fight," he told reporters, referring to the ban on campaigning before the vote. "I am still convinced that power will return to the people some day," he added. However millions voted in favor of the military's charter, especially in the capital and the south. Thailand has a long history of turbulence. The military has successfully seized power 12 times since the end of absolute monarchy in 1932 and this constitution will be the kingdom's 20th. But the latest chapter in the political crisis — dubbed the "lost decade" — has been particularly painful. Since a 2006 coup toppled Prime Minister Thaksin Shinawatra, Yingluck's billionaire brother who is now in self-exile, power has flipped between elected governments linked to him and rule by the army and its establishment supporters. Shinawatra parties have won all general elections since 2001, scooping up votes of the rural poor and urban working class with policies promising greater wealth and opportunity. Their success has riled the military and its political friends who accuse the clan of debasing the country with graft and nepotism and have hit back through coups and the courts. The tension has been compounded by the frail health of 88-year-old King Bhumibol Adulyadej, as elites jostle ahead of the transition. After casting his own vote in Bangkok junta leader Prayut urged people to vote, adding: "This is democracy so all eligible voters please come out." Prayut banned open debate on the contentious charter and scores of people have been arrested under a special law to curb opposition. The most divisive clauses call for a junta-appointed senate — including six seats reserved for military commanders — to check elected lawmakers and increased powers for courts, which are already accused of political bias. Another clause makes it easy to begin impeachment proceedings. Junta opponents believe the charter will further warp democracy. They fear the appointed senate will straitjacket elected politicians while a new proportional representation voting system could produce weak coalition governments. "The coup makers tore up the old constitution and robbed us of our rights, promoting themselves to control the government," ‘No' voter Ohm Kontaogan, 35, said in Bangkok. It is a "robber's constitution," he added. At one Bangkok polling station an activist was arrested for deliberately spoiling his ballot paper. Video footage showed the man wearing a "No Coup" t-shirt and shouting "Down with dictatorship, long live democracy." Prayut had promised to hold elections in the summer of 2017, whether or not the charter was passed. But his previous election date promises have slipped.