The steady rise in undecided voters, judging by recent opinion polls, looks to be the most significant political development shaping the run-up to the next general election.

While political parties are making promises, adjusting campaign messages, and sharpening their attacks on rivals, a growing proportion of the electorate remains unconvinced — if not outright disillusioned.

This expanding bloc of undecided is not merely a statistical footnote; it reflects a simmering frustration with a political class that voters increasingly view as lacking credibility, competence, or substantive achievements.

This phenomenon is not new. Elections across the region have witnessed cycles of disenchantment, especially when governments fall short of expectations or when opposition groups fail to articulate viable alternatives.

But the scale of those undecided is different. Survey after survey shows rising numbers of respondents expressing doubt about who deserves their support. For many, the choice is not between Party A or Party B — it is between voting or disengaging altogether.

Most voters in Central Plains provinces remain undecided over who the next prime minister should be, though Bhumjaithai Party leader Anutin Charnvirakul continues to trail People’s Party frontrunner Natthaphong Ruengpanyawut, according to a National Institute of Development Administration (Nida) survey last month.

The survey was carried out between Nov 10 and 13 among 2,000 eligible voters across 17 central provinces. including Nonthaburi and Pathum Thani, but excluding Bangkok.

It found that 35.65% had no preferred candidate. Despite this uncertainty, Mr Natthaphong led the declared choices with 19.6% support, reflecting the People’s Party’s steady rise in the region.

The Nida Poll also surveyed 2,000 voters from Chachoengsao, Chon Buri, Rayong, Chanthaburi, Trat, Nakhon Nayok, Prachin Buri and Sa Kaeo provinces from Nov 13–18.

When asked who they would support as the next prime minister, 39.75% said they had not yet identified a suitable candidate — the largest share by a wide margin.

Behind all this are several intertwined factors, a source said.

First is political volatility fatigue. Over the past decade, voters have weathered frequent leadership changes, legislative gridlock, and recurring political conflicts. Each round of campaigning tends to revive unresolved tensions without offering convincing solutions.

Second, there is a noticeable loss of confidence in the parties. The ruling bloc has struggled to deliver clear, measurable improvements to people’s lives during a period marked by economic uncertainty, rising household debt, and concerns over public administration.

Meanwhile, opposition parties — despite gaining some traction — often fail to capitalise on momentum, leading voters to question whether any party can effectively govern.

Third, the electorate has become more informed and more sceptical. Social media has expanded access to political information, but also amplified cynicism by exposing scandals, broken promises, and contradictory statements by politicians. In an environment where every claim is scrutinised in real time, trust is hard to come by

Parties have adjusted their messaging in several ways. They pivot to economic relief and household welfare, hoping that direct benefits — be they subsidies, tax breaks, or debt restructuring — can persuade voters feeling financially

The parties are softening ideological rhetoric to appeal to moderate voters uncomfortable with polarising themes and resorting to rebranding leadership images, with some parties like the Democrats promoting younger candidates or technocrats to project a sense of renewal. Parties are also expanding grassroots engagement, particularly in provinces where there’s a high concentration of undecided respondents, the source observed.

Yet these efforts often clash with a fundamental hurdle: parties lack tangible achievements that resonate with voters. Many of the flagship policies announced in prior campaigns were either diluted, delayed, or abandoned. As a result, voters remain sceptical, refusing to commit based solely on promises.

The ruling BJT may have started out strong on delivering economic policies via Finance Minister Ekniti Nitithanprapas and Commerce Minister Suphajee Suthumpun. However, the disastrous floods in Songkhla’s Hat Yai district have taken their toll on people’s confidence in the government.

Underscoring undecided voter numbers is a deeper crisis of credibility. For years, voter loyalty has been weakened by perceptions that politicians place personal survival and coalition bargaining over long-term governance.

Coalitions assembled through horse-trading rather than a shared policy vision reinforce public belief that parties exist to secure power rather than solve national problems, the source said.

This explains why the undecided demographic spans across age groups, regions, and socioeconomic classes. Young voters, traditionally mobilised by reform-oriented movements, feel disappointed by legislative setbacks and internal party conflicts. Middle-income earners struggling with cost-of-living pressures see little difference between competing economic platforms. Older voters, once reliable supporters of establishment parties, question whether these parties can still guarantee stability.

If undecided numbers keep growing, it would set the stage for a volatile final few weeks of the next election campaign. Late decision-making can lead to rapid shifts in poll rankings, sudden surges, or unexpected dips in support.

If undecided voters ultimately favour a single party, it could create a landslide-like effect. If they distribute themselves evenly, the election may produce another fragmented parliament, complicating coalition building.

There is also the possibility that a significant portion may remain disengaged and opt not to vote. A low turnout would raise questions about the legitimacy of the next government and could prolong the cycle of disenchantment.

The core issue, according to the source, is that parties have not addressed the structural reasons behind declining trust. There is a lack of transparency in policymaking, and campaign financing continues to alienate voters.