[4][5] Born in Songkhla Province, Chaithawat was educated as an engineer before entering journalism as the founder of Same Sky Books, a political magazine.

After Pita's election as Prime Minister was blocked by the Senate, the Pheu Thai party formed a new coalition that excluded MFP.

Chaithwat was later elected as party leader unopposed after Pita Limjaroernat was suspended from the National Assembly due to a Constitutional Court order in September.

[13] Under Pita and Chaithawat, the Move Forward Party won the most seats (153) in the election, and amassed about 38% of the popular vote.

[15] A memorandum of understanding, a first in the history of Thai politics, was signed by all cooperating parties, which included, among other things, the nomination of Pita as prime minister upon the meeting of the National Assembly in July.

The Thai Senate, composed of members appointed by the military after the 2014 coup, maintained voting power in the election of the prime minister.

The party was also under small threats of dissolution due to its proposed lèse-majesté (royal insult law) reforms.

[22] With Move Forward no longer part of the post-election coalition, Pheu Thai assumed responsibility over the government formation, nominating Srettha Thavisin, a real estate tycoon, as their candidate for prime minister.

[26] On 15 September, Pita announced he would resign as party leader amidst his ongoing legal issues over his alleged campaign law violations.

[32] In late December, Chaithawat stated he enjoyed his work as Oppsoiton Leader, but reiterated he would be willing to step aside were Pita to be acquitted in his iTV Constitutional Court case.

[35] Although a general meeting of the party did occur on 6 April, no leadership election was held, and Chaithawat remained as opposition leader.

[37] He accused the government of undermining the justice system through double-standards and ignoring its policy statement presented to parliament.

[38] In May 2024, Chaithwat said the party would be ready to re-nominate Pita for the role of Prime Minister were Srettha Thavisin to be removed in a "political accident".

[39] Meanwhile, the party was preparing for a separate Consituional Court case, in which they were accused of attempting to overthrow the monarchy of Thailand through their promises to amend lèse-majesté laws.

[40] At 2:57 PM, the court ruled that Move Forward's campaign promise to amend the lèse majesté was unlawful and tantamount to attempting to overthrow the monarchy, and ordered the party to cease related activities.

[47] In May Chaithawat stated that an alternative party was ready to accept Move Forward's 151 members of parliament, should the court order its dissolution.

[58] The party had invited the public to their headquarters in the Hua Mak district of Bangkok to listen to the ruling live.

[60][61] He stated that: "The ruling sets a dangerous precedent for the interpretation of the Constitution and laws, posing a risk to the core principles and fundamental values of our future democratic system with the King as head of state...The long-term implications may transform our democratic system into another form.

"[62] That evening, Chaithawat returned to Parliament to inform the House that he and 4 other MPs could no longer perform their duties as they had been banned from political activities in the country.

[68] Chaithawat believes that the digital wallet scheme implemented by the Srettha government could hurt the Thai economy by increasing public borrowing.