The state planning agency also said it had not seen any political party focusing on basic policies under constitutional requirements although these policies - involving education, public health and environment - play a very important in Thailand's competitiveness and development.

Voters should consider the reality of policy implementation as the promises being made required massive investment, said Arkhom Termpittayapaisith, the NESDB secretary-general.

Once a political party forms a government, he said, it will discover the many constraints on the fiscal budget. The investment budget accounts for just 17-18 percent of the total budget, or 400-450 billion baht, providing little room of flexibility when it comes to carrying out new investment projects, he said.

The government also needs to implement policies that balance the interests of different groups such as business and low-income earners, he said, referring to pledges by the main contenders to raise minimum wages substantially.

Mr. Arkhom said parties should tell the public that increases in the minimum wage depend on the tripartite wage committee comprising business, labour and government representatives.

Another impact from the increase in minimum wages would be on goods prices, and too high a rise would add further pressure to inflation rates.

Besides making promises to attract voters, he said, political parties should explain to their voters how they intend to implement those policies.

When it comes to basic policies on education, Mr Arkhom said, the government needs to consider improving the system to meet the demands of industries and also ensure the quality development of the workforce.

The quality of public health should be highlighted as well, with a focus on educating people about types of consumption behaviour that can lead to more health problems.