All past governments must take responsibility for the poor results of Thai students in recent international tests, according to Prime Minister Srettha Thavisin.
His government, which took office three months ago, will strive to resolve the problem and improve the Thai education system, he said.
The prime minister was referring to the latest Organisation for Economic Co-operation and Development's (OECD) Pisa test that saw Thai students' scores hit 20-year lows.
Thailand is one seven countries with an already deteriorating reading performance before the pandemic. That group also includes Costa Rica, Finland, Iceland, the Netherlands, the Slovak Republic and Sweden.
Mr Srettha said many people have criticised Thai education for its poor quality, particularly in terms of curriculum and teacher quality, but no one has taken serious action to fix it.
"More than a million children have been forced away from the education system due to the Covid-19 pandemic. We will have to help them return," he said.
"Big companies should also help support Thai education."
Siripong Angkasakulkiat, assistant spokesman for the Education Ministry, blamed the pandemic for lowering the performance of Thai students taking the test as they had been forced to study online and lost concentration when learning.
This has also affected their reading and critical thinking skills, he said.
He said most students with low scores were found to be studying in schools offering educational opportunities to children in the provinces, particularly those operating under the Office of the Basic Education Commission and local administrative organisations.
Meanwhile, the scores of students in some schools that focus on science achieved high scores, even higher than those of their peers in Singapore. As a result, the teaching models of these successful schools need to be applied to other schools in the country, Mr Siripong said.
Prof Sompong Jitradab, an education scholar, urged the premier to urgently resolve the education issues, especially for such subjects as English, mathematics and science.
"Unfortunately, the Education Ministry only concentrates on pushing learning about history and subjects related to civic duty. Why?" he asked.
He urged the government to take action to reform education, something that has been talked about for decades but never implemented.
The government needs to improve the learning environment for students in provincial schools to encourage young people there to attend class and avoid illicit drugs and other illegal activities as these problems may cause them to drop out, he said.