BANGKOK • It was not only the moves to ban Thailand's most vocal opposition party that brought Gift onto the street for the first time.

The 25-year-old landscape architect was also stung by taunts that her generation was not brave enough to go beyond online comments in challenging the army-dominated establishment's enduring hold since elections to end junta rule.

She and other first-timers joined veterans of Bangkok's turbulent decades of street protests as thousands rallied at the weekend in the biggest demonstration since a 2014 coup.

"They say the new generation exists only on social media, so we're out here to show we have a voice too," said Ms Chattip Aphibanpoonpon, who like many Thais goes by her nickname - Gift. "The conflict used to be about people on two sides. Now it's a battle between the military and the people. It's not fair."

In a country long roiled by bloody protests - and punctuated by coups in the name of ending them - last Saturday's peaceful rally was a reminder of the tension building again rapidly between the establishment and those seeking change.

At the forefront is 41-year-old auto-parts billionaire Thanathorn Juangroongruangkit, who was recently banned as a Member of Parliament and whose Future Forward Party faces dissolution. In both cases, party supporters believe the legal grounds are spurious and designed to eliminate a challenge to Prime Minister Prayut Chan-o-cha, the former junta leader who stayed on after March elections which the opposition says were manipulated.

"This is just the beginning," Mr Thanathorn told protesters, who spilled across walkways and staircases between a Bangkok mall and art gallery.

The protest was called just a day before - as a "flash mob" - via Mr Thanathorn's Facebook Live stream and a single tweet that got nearly 67,000 retweets and 41,000 likes.

It is Future Forward's social media heft - as well as pledges to change the army-drafted Constitution and to end conscription - that has the army worried.

Army chief Apirat Kongsompong has said Thailand faces a situation of "hybrid war" against a movement he accuses of seeking to use social media to rally people against the army and the powerful palace.

"The young people are enthusiastic and determined and full of energy, but they don't see through politicians' tricks," said Mr Warong Dechgitvigrom, a right-wing politician who sees Future Forward as an existential threat to Thailand and its monarchy.

Government spokesman Narumon Pinyosinwat said that the party should express its opinions through Parliament rather than on the street, but she did not expect the situation to escalate.

The turnout was a reflection of growing political engagement among young people, but would not necessarily spiral, said Dr Titipol Phakdeewanich, dean of Ubon Ratchathani University's political science faculty . "I don't see it becoming a serious movement like in the past or on the scale of Hong Kong."

Widespread coverage on social media underscored the extent to which the opposition leads the government on that front.

Mr Thanathorn has 1.1 million Facebook followers and 670,000 on his @Thanathorn-FWP Twitter account, compared with Mr Prayut's 770,000 and 55,000 for @prayutofficial on Twitter.

That social media heft helped Future Forward into third place in the March polls, after traditional opposition party Pheu Thai and a pro-army party backing Mr Prayut.

The question has been whether online activism would translate into a readiness to take to the street. And it has not been only establishment parties casting doubt.

Before Saturday's rally, activist Anurak Jeantawanich challenged Future Forward supporters as "only using hashtags, but afraid to take to the streets". If fewer than 2,000 people showed up, "you might as well just let your party be disbanded", he said.

Several thousand gathered, if not the 10,000 plus claimed by organisers.

"I'm come from social media," read a placard held by Mr Pisit Iewlatanawadee, a 29-year-old business owner from Nakhon Pathom in central Thailand. "We're not only good at typing. We also want to participate in opposition to authoritarian government," he said.

Mr Rafah Supanphong, 25, told Reuters: "They keep saying we are brave only on online platforms, it encouraged me to come out."

The younger protesters joined many older "red shirts" who recalled years of street clashes and bullets in support of ousted populist prime minister Thaksin Shinawatra in clashes with pro-establishment "yellow shirts".

Earlier, the Pheu Thai Party of the self-exiled Thaksin said that it backed the rally by "younger brother" Thanathorn.

A small group of policemen challenged the rally organisers for holding a demonstration without notice, but made no attempt to stop it. Yesterday, police said they were investigating if the law had been broken.

Future Forward said it had not been a political rally, so it did not need to give notice.

REUTERS