Thai Prime Minister Prayuth Chan-O-Cha (C) greets people at Lumphini Park in Bangkok on March 20, 2019, ahead of the March 24 general election. Jewel Samad | AFP | Getty Images

Voters in Thailand are set to choose their next government on Sunday after five years of living under military rule. The March 24 vote comes after the ruling junta repeatedly postponed general elections after it overthrew an elected government in 2014. Thais have reacted enthusiastically to the long-awaited vote: Around 87 percent of the 2.6 million people registered for early voting cast their ballots in the last few weeks, according to various reports. Several political analysts predicted that total voter turnout could exceed 80 percent to reach an all-time high in Thailand. But a change in the country's constitution and electoral rules that favor pro-military political parties mean Thailand still has a long way to go to shed the influence of its powerful army, analysts said. "The rules have been written to maintain military supervision over Thai politics," Thitinan Pongsudhirak, a political science professor at Thailand's Chulalongkorn University, told CNBC's Sri Jegarajah on Friday. Even then, the outcome of the election is unpredictable and could reignite tensions between supporters of the different political fractions in Thailand, added Pongsudhirak. Southeast Asia's second-largest economy is no stranger to military takeovers and another coup cannot be ruled out if violence and protests break out once again after the vote, the professor said.

The predictions

The Sunday vote will determine 500 members of the House of Representatives, the lower chamber of Thailand's legislative branch. The ruling-junta will appoint the 250-member Senate, or the upper house. The election is set to be a contest between three main political fractions: A pro-military camp, an anti-military group and parties that are neutral or undecided about the side with which they would align.

Harrison Cheng, associate director and lead analyst for Thailand at consultancy Control Risks, outlined his predictions for the major party in each of the fraction: The pro-military Palang Pracharat Party, which named current Prime Minister Prayuth Chan-o-cha as its candidate to lead the country, is expected to win up to 70 seats.

The anti-military Pheu Thai Party, which is linked to exiled former Prime Minister Thaksin Shinawatra, will likely be the best performer with 130 to 200 seats.

The neutral Democrat Party, led by another former prime minister, Abhisit Vejjajiva, is forecast to secure between 80 and 120 seats. None of the parties are expected to single-handedly win enough seats in the House to form a government, partly due to the way votes will be counted after a change in the constitution in 2017. So, the 250 appointed senators will join their colleagues in the House to select the next prime minister to lead the next government. That means Prayuth is likely to remain in office even if the party supporting him does not win big in the election. Assuming the current prime minister has the backing of all 250 senators, he will only need 126 supporters in the House to be take the helm again.

Election meddling

Even then, Prayuth's return to office will likely not be a smooth process, noted Pongsudhirak. If the retired general assumes the role without a clear mandate from voters and against the backdrop of overwhelming support for anti-military parties, Thailand could run into a constitutional crisis, the professor said. "Nothing is straightforward in this election. I think there'll be a lot of controversies" even before the final election results are announced, he said.

Thailand's Election Commission has until May 9 to finalize the outcome of the March 24 vote. In between, the current ruling junta led by Prayuth is still in power and election candidates could still be banned or have their votes invalidated, noted Cheng. Such meddling by the junta is likely if the largest anti-military party, Pheu Thai, is found to be leading in the votes, he added. "More radical possibilities include nullifying the entire election results and setting a new date for a national revote, or worse, a military coup that seeks to delay the return to civilian rule," he explained. "Even if the military accepts the reality of a (Pheu Thai)-led winning coalition, it would be tempted to delay the formation of a new government."

The Thai economy

The uncertainties surrounding the upcoming general election are clouding Thailand's economic outlook, economists from consultancy Capital Economics wrote in a recent note. "Whoever wins, the shift towards economic populism is likely to continue, delaying reforms needed to raise productivity growth and deal with the worsening demographic outlook," they said.

Supporters of Thai opposition party, Pheu Thai, at a political rally in Bangkok the general election on March 24. SOPA Images | LightRocket | Getty Images