Pheu Thai and Move Forward are expected to win more than 300 of the 400 constituency seats between them, the survey by Nation Poll found.
The House of Representatives has 500 MP seats – 400 elected from constituencies and 100 from the proportional party-list system.
Nation Poll is part of the Nation Group. The Nation is its English-language news outlet.
The poll was conducted from April 24 to May 3. It surveyed 36,243 eligible voters in Bangkok and 78,214 outside the capital. It has a margin of error of plus or minus 3% in Bangkok, plus or minus 5% in eight major provincial cities, and plus or minus 7% for all other constituencies, pollsters said.
Pheu Thai is likely to win as many as 247 of the 400 constituency MP seats in the May 14 election, while Move Forward is on track to win 79 MP seats.
Decline in undecided voters
The number of respondents who said they remained undecided fell from 32% in the first countrywide Nation Poll in early April to 8.6% in the second poll. However, the number of voters who said they were undecided comprised a majority in 18 of the 400 constituencies surveyed, Nation Poll said.
The poll forecasts the Democrat Party to win 15 constituencies, while its coalition partner Bhumjaithai is on track to win 12.
The opposition Prachachat Party will also win 12 seats, pollsters said.
The United Thai Nation Party – whose candidate for premier is incumbent Prime Minister Prayut Chan-o-cha – is expected to win only seven of the 400 constituency seats.
The ruling Palang Pracharath Party will fare even worse, the poll found. It is expected to win only five constituency seats. Another coalition member, Chart Thai Pattana, is forecast to win a mere four seats.
Chart Pattana Kla is forecast to win one seat.
Pollsters cautioned, however, that the margin of error in the survey could result in fewer seats for the two main opposition parties. Pheu Thai could win as few as 228 of the 400 constituency seats and Move Forward’s total could be as low as 52.
In hotly contested constituencies, conservative parties may edge out Pheu Thai and Move Forward if liberal voters split evenly between the two parties, pollsters said.
Taking into account the survey’s margin of error, the number of undecided voters and the possibility of Pheu Thai and Move Forward splitting liberal voters in some constituencies, conservative parties could see some gains, pollsters said.
The Democrats could win between 19 and 42 constituency seats.
United Thai Nations could win 13 to 36 seats.
Bhumjaithai could win 16 to 39 seats.
Palang Pracharath could win six to 29 seats, and Chart Thai Pattana could win between four and 27 seats..
The survey found that the races will be very tight in 65 constituencies. The gap between the expected winner and second- and third-placed candidates in these constituencies could result in upsets that favour conservative parties, pollsters said.
'Strategic mistake'
Pollsters concluded that it was a strategic mistake for coalition parties to compete against each other in virtually all constituencies. Avoiding competing directly against each other would have allowed conservative voters to coalesce around one conservative candidate in a constituency, pollsters said.
This “strategic mistake” will cost coalition parties many MP seats, pollsters said.
They pointed to the 11 upper southern provinces where favourite candidates from the Democrats, United Thai Nation and Palang Pracharath may be defeated by Pheu Thai or Move Forward candidates because they are splitting the conservative vote.
The ration of conservative to liberal voters in the 11 provinces is two to one, pollsters said. There are 14 provinces in the South. The upper south excludes the three Muslim-majority provinces that border Malaysia.
In Bangkok, Pheu Thai and Move Forward are expected to dominate most of its 33 constituencies, with Pheu Thai taking the lead over Move Forward.
Pita takes lead for PM
Move Forward leader Pita Limjaroenrat emerged as the most popular prime ministerial candidate in the poll. He was selected as the preferred candidate for prime minister by 29.4% of respondents, surpassing Pheu Thai’s PM candidate Paetongtarn Shinawatra. Her support fell to 27.5%.
In the first Nation Poll, Pita trailed Paetongtarn by 17 percentage points.
Prayut was the most popular choice for the top political job among respondents of the 11 upper southern provinces, followed by Pita.
Prachachat Party leader Wan Muhammad Noor Matha is the top PM choice among voters of the three southern border provinces.
Prachachat is likely to win most of the House seats available in the three southernmost provinces: Yala, Pattani, and Narathiwat, the survey found.
Move Forward has a good chance of making inroads in Pheu Thai’s strongholds – the North and the Northeast – as well as in the South, which is dominated by the Democrats. It could also upset candidates for the United Thai Nation in some constituencies, pollsters said.
Move Forward will likely make history by sweeping every MP in some provinces, pollsters said.
Strongholds in doubt
Parties are losing their grip on their traditional strongholds, pollsters said.
Bhumjaithai may lose seats in Buriram.
Pheu Thai may lose seats in Chiang Mai.
Chart Thai Pattana may lose seats in Suphan Buri, and the Democrats may lose seats in Songkhla.
Pollsters said vote buying remains a factor in the upcoming election and could even influence the results in some areas.
A significant number of respondents said they had yet to decide who to vote for because they were waiting to see “who will give more”.
The 2nd Nation Poll was released on May 5, with participants including 115,339 eligible voters - 35,969 in Bangkok and 78,214 outside the capital.
It has a margin of error of plus or minus 3% in Bangkok, plus or minus 5% in eight major provincial cities, and plus or minus 7% for all other constituencies
The poll, which used interviews to gather information, was carried out between April 28 to May 3 in Bangkok and between April 24 to May 3 in other provinces.