That would extend the Thai Royal Army’s outsize influence in the politics of the coup-happy kingdom.

This Week in Asia takes you through six key questions about Sunday’s election.

WHY SO IMPORTANT?

The 2006 seizure of power also brought to the fore the fierce battle for power between the ruralist bloc behind Thaksin Shinawatra, the billionaire prime minister in power at that time, and the nexus of courtiers, old money and urban elites that reviled this populist movement.

Both sides – competing in Sunday’s election under new guises – have cast this vote as their ultimate battle.

Prayuth is the favoured prime ministerial candidate of the Palang Pracharat Party, which is seeking to rule under a quasi-democracy that keeps the generals well within the corridors of power rather than shafting them aside.

Aside from that battle royale billing, the vote is also the first being held under the aegis of King Maha Vajiralongkorn, who took the throne after the death of his father Bhumibol Adulyadej.

His father was respected for being the glue that kept the country together despite near-constant political upheaval during his seven-decade rule. Vajiralongkorn’s mettle as a neutral arbiter among the competing forces vying for power in the country remains unproven.

WHO IS VOTING?

A total of 52 million people out of a population of 69 million are eligible to vote. Some 2.2 million people who opted for early voting cast their ballots last Sunday.

The two major camps each have their own vote banks. The bloc loyal to Thaksin, the exiled former prime minister, relies on support from the largely agrarian northeast, where voters remain loyal to the 69-year-old for the slew of economic sweeteners for the poor he rolled out during his time in power. His sister Yingluck continued that legacy during her 2011-2014 stint in power.

Prayuth, who is banking on the pro-military Palang Pracharat Party to emerge victorious, will count on support from urbanites who loathe the Shinawatras for diverting tax dollars to the poor.

The establishment also revile the Shinawatras for purportedly advancing the interests of their vast business empire during their time in power.

Most of Bangkok’s 10 million people are likely to vote against the Shinawatras.

Observers meanwhile have trained their focus on a narrow group of electors – the eight million Thais who will be voting for the first time in their lives. Those born after 1996 would not have had a chance to participate in an election – the last vote was in 2014 – but grew up in the midst of the political violence that roiled the country in the 2000s.

The big question is who these voters will back. It may not be the Shinawatras or the pro-military faction. One dark horse cited as the young people’s choice is the Future Forward Party led by the charismatic autoparts billionaire Thanathorn Juangroongruangkit.

THE NUMBERS GAME

A 2017 constitution written by the ruling junta has created a electoral system that arguably is the most complicated in the country’s history. Supporters of the Shinawatra camp say the system is designed to ensure the Shinawatra clan’s Pheu Thai Party, the country’s biggest party, does not emerge victorious. Their faction won the 2001, 2006, 2007, 2011, and 2014 polls.

There are 500 parliamentary seats up for grabs this time around: 350 constituency seats and 150 party-list seats. The encumbrance for Pheu Thai comes in the party-list seats. In previous elections, the apportionment of the 150 party list seats was simple as voters had two ballot slips – one to choose their constituency lawmaker, and one to choose their party of choice. The latter would be used to determine the apportionment of party list seats. This time round, there will be only one ballot slip. Party list allocations will be determined by the popular vote count for the 350 constituency seats, but for the first time, there will be a limit to the number of party-list seats a party can win.

This will be determined by a “value” given to each seat, depending on the total turnout. If, for example, there were 41 million electors, the value would be 82,000 – the total number of votes divided by 500, the total number of seats. Total seats – constituency and party-list – cannot be disproportionate to a party’s popular vote. In effect, this means a large, national-level party like Pheu Thai cannot have two bites of the cherry by winning constituencies and a large proportion of the party list seats. The system benefits mid-sized parties that could enter coalition with Palang Pracharat.

CONTROLLABLE SENATE

Another element of the electoral equation has to do with the unappointed Senate. Under the 2017 constitution, Prayuth’s junta will choose all 250 members of the upper house. That would not be too much of a problem – if not for the fact that these unelected individuals each have a vote in who becomes prime minister. Palang Pracharat could get by with a mere 126 parliament seats, as with the support of the 250 senators it would have the simple majority in both houses to meet its objective – keeping Prayuth in his current job. After the election, a joint session of the 500-seat parliament and the 250-seat, military-appointed Senate will pick the prime minister.

There are longer term repercussions too. The junta-appointed Senate’s term lasts five years. This means it will have a say in who becomes the prime minister after the 2023 elections as well. The Senate will also act as the steward of a 20-year economic strategy crafted by Prayuth’s administration that the next five elected administrations must adhere to. Critics of this provision say it ties the hands of democratically elected governments in crafting economic policy.

WHO ARE THE BIGGEST PLAYERS?

Naturally, Prayuth is the big name going into Sunday’s electoral battle. On the opposing side, spearheading Pheu Thai, is long-time Shinawatra loyalist Sudarat Keyuraphan. The 57-year-old is no puppet however, having carved out a loyal personal following because of her reputation as a political street fighter. She emerged as top dog in her party after Yingluck fled the country in 2017 to escape criminal charges she said were trumped up. Another heavyweight in Pheu Thai is former Transport Minister Chadchart Sittipunt, viewed by some as a better prime ministerial candidate than Sudarat. Outside the Pheu Thai circle, Prayuth is up against the star power of Thanathorn, whose rallies have attracted thousands enamoured by his oratory skill and promise of a new politics bereft of the Shinawatra-military rivalry.

Elsewhere, Abhisit Vejjajiva, leader of the pro-establishment Democrat Party, has raised eyebrows after he said he was opposed to Prayuth staying on as prime minister. Abhisit himself was prime minister of a minority government from 2008 to 2011 with the support of the royalist-establishment, and his party has long viewed the Shinawatras as foes – leading observers to believe he will cooperate with the junta leader after the election even though at the moment he insists otherwise.

Thaksin, now the country’s number one political outcast, is not a direct player in the vote, but his presence will loom large on Sunday. He is a fugitive and has been in self-exile since 2008. Pheu Thai’s stalwarts continue to refer to him as “boss” and several of them are making a whistle stop trip to Hong Kong for the wedding of the politician’s youngest daughter Paetongtarn “Ing” Shinawatra on Friday. Thaksin has kept his thoughts on the polls to himself. When he spoke to international media last year about Pheu Thai’s prospects, Prayuth’s junta issued veiled threats that it would investigate the party for being influenced by “outsiders”.

WHAT HAPPENS NEXT?

Pre-election polls have thrown up a spectrum of post-election scenarios. Siripan Nogsuan Sawasdee of Chulalongkorn University, offers this prediction: 200 seats to Pheu Thai, 100 seats to Abhisit’s Democrats, 70 to Palang Pracharat, 50 to Thanathorn’s Future Forward Party, with other parties capturing the rest of the 500 parliamentary seats. Thitinan Pongsudhirak, the Thai political commentator most known outside of his country, said in a commentary on Wednesday that

the “most probable scenario” post-election would be a “junta-backed and Senate-supported coalition government, most likely under Prayuth, with most parties included, except the anti-junta groups”.

“But because it is unlikely to command a sufficient number of MPs for stable rule, parliamentary deadlock will ensue in the lower house, with all roads leading to another constitutional crisis in the coming months,” he added.

Voting booths will open at 8am on Sunday and close at 5pm. The Election Commission has said 95 per cent of the votes should have been counted by 8pm. However, results will not be formally endorsed by the commission until later. Prayuth’s junta will remain in place until after the coronation ceremony of King Maha Vajiralongkorn scheduled for May 4-6. The poll results will be formalised after that.

Some observers say Prayuth may use special powers granted to him as junta chief to prolong his tenure as prime minister if the poll results do not go in his favour. Another possibility is a fresh coup by the increasingly assertive army chief Apirat Kongsompong. ■