Shouting “Nayok Pita”, or “Prime Minister Pita”, several thousand Move Forward supporters on foot, cars and motorcycles swarmed around the truck carrying Thailand’s latest star politician as it travelled from the symbolic Democracy Monument.

An inflatable dinosaur – a symbol of the old powers his movement seeks to dislodge – was released above Pita’s head and flowers were passed to the Harvard graduate after he gave a speech thanking adoring supporters.

“He will change the country,” said a grinning 16-year-old who gave one name as Pim, one of hundreds of school pupils in uniform - a sign of the reach of Move Forward’s youth appeal. “The old generation has to let the party be the government now.”

Move Forward’s change narrative of demilitarisation, protecting personal and political freedoms, hacking back monopoly businesses and – crucially – reforming the ‘112’ royal defamation law which shields the ultra-rich Thai monarchy, appeared to have cut through well beyond their youth base.

The Election Commission on Monday said with 99 per cent of votes counted, Move Forward Party had won the most seats (151), edging out Pheu Thai (141). Cannabis liberalisation advocate Bhumjaithai was running in third (71) giving it a possible deciding hand in which way the next government tilts.

The conservative Phalang Pracharat, which led the last coalition government, secured just 40 seats. While the party of Prayuth Chan-ocha, the coup-making former general-turned-premier at the heart of a decade of decay, secured 36, enough to keep the door back to power ajar.

03:51

Thai opposition parties take the lead in election as voters reject military-backed rule

Thai opposition parties take the lead in election as voters reject military-backed rule

Pita proposed an alliance of six parties, including Pheu Thai, that would command 309 seats, with him as prime minister. That would be short of the 376 seats needed to ensure he was elected to the top job.

The Election Commission said it had 59 days to ratify the vote, raising the potential of changes ahead to the electoral landscape.

Asked about the upper house senate controlled by military-aligned parties, Pita said all sides must respect the election outcome and there was no use going against it.

“I am not worried but I am not careless,” he told a press conference. “It will be quite a hefty price to pay if someone is thinking about debunking the election result or forming a minority government.”

Shinawatra bust?

The turnout for Move Forward took chunks from the southern heartlands of the conservative right but also the northern bastion of Pheu Thai, the long-standing pro-democracy vehicle of billionaire ex-premier Thaksin Shinawatra, who wants to return to Thailand after 17 years in self-exile.

“Pheu Thai fought the wrong war, the populism war that it already won,” Thitinan Pongsudhirak, of Chulalongkorn University told Reuters. “Move Forward takes the game to the next level with institutional reform. That’s the new battleground in Thai politics. This is a staggering result. It’s historic.”

Move Forward’s newcomer candidates also beat Thailand’s dominant “baan yai” political clans in their own backyards, who normally translate patronage power into bundles of votes which they take into government.

“Congratulations to MFP for your beautiful win in this election,” Pheu Thai candidate and veteran pro-democracy activist Chaturon Chaisang tweeted on Monday. “The fight with dictatorship has come to a new chapter. Thai society is about to change. Thais have spoken up that they want democracy.”

02:37

From the streets to parliament, young Thai activists shake up national politics

From the streets to parliament, young Thai activists shake up national politics

But experts warn there is still a long way to go before a pro-reform government can be formed, in a system crafted to give the military and its allies a back door into power in the event of a heavy election defeat.

In a 700-member bicameral chamber, the 250-member appointed Senate has a role to play in deciding who has a majority and later voting for a prime minister. The Senate was appointed by Prayuth and its members are widely expected to get behind him or another conservative leader if they are able to patch together a coalition of smaller parties.

All eyes will now turn to the institutions which underpin the establishment – the Electoral Commission, and Constitutional Court – which both have long histories of dissolving pro-democracy parties and banning key leaders after polls.

Generation game

The army, which sees itself as the protector of the palace, meanwhile lurks in the background in a country where a coup has struck every seven years on average since 1932.

Prayuth, 69, ran a negative campaign that pulled heavily on the fear of older conservatives, saying Thai values, religion and the monarchy are under existential threat.

He has repeatedly said he will “go home” if he does not perform well in the election, but experts say he is unlikely to cede power easily.

He is an arch-royalist who has throughout his nine years in office refused to negotiate with young activists and says the royal defamation law must not be touched to protect the kingdom’s apex institution.

Additional reporting by AFP, Reuters