The Pheu Thai Party, which came second in the general election, has dumped the election-winning Move Forward Party and will move to form its own coalition government because the MFP insists on amending the lese majeste law.

Pheu Thai leader Cholnan Srikaew announced the move on Wednesday afternoon.

The two parties were the main players in an eight-party alliance formed by the MFP in its bid to form a  government. MFP has 151 House seats and Pheu Thai 141. Their alliance had 312 of the 500 House seats.

The MFP failed to win a majority vote from the House and the Senate after nominating its leader Pita Limjaroenrat for prime minister on July 13. It then allowed Pheu Thai to take the lead in the formation of a coalition government.

Most of the appointed senators and many of the elected MPs of other parties disagreed with its insistence on changing Section 112 of the Criminal Code, the lese majeste law.

The Pheu Thai leader told a press conference on Wednesday afternoon that after MFP failed to get the needed parliamentary support, the eight-party alliance assigned Pheu Thai to get more support from the other parties and senators, so a government could be formed.

"It turns out that they do not accept any change to Section 112 and some parties even stated that they will not join a government with Move Forward anyway," Dr Cholnan said.

Therefore, Pheu Thai had told Move Forward during a meeting on Wednesday morning that it was withdrawing from the eight-party alliance and would nominate its own prime ministerial candidate, Srettha Thavisin, to the parliament.

"Pheu Thai and Mr Srettha will keep Section 112 intact and the new government will not have Move Forward in its coalition," Dr Cholnan said.

He said the discussion with Move Forward on Wednesday morning was held in a positive atmosphere.

"Pheu Thai will try to gather enough votes (in the parliament) and Move Forward will be in the opposition," he said.

He would announce what parties would be in the coalition on Thursday.