The opposition is calling for the revocation of the emergency decree as it proposes an extraordinary parliamentary session to discuss the political conflict.
The government earlier this week announced a ban on gatherings of more than five people under the emergency decree as a response to recent unrest in Bangkok, which saw the arrests of pro-democracy protest leaders.
After a joint meeting of opposition parties on Thursday, Pheu Thai Party leader Sompong Amornvivat said the decree became effective at 4am yesterday but it was illegitimate.
Protest leaders dispersed from protest scenes about midnight, while protesters at Government House only left the scene about 5am.
The opposition is also calling for the immediate release of the protest leaders, asserting they did nothing wrong.
"We agree that peaceful ways should be employed," Mr Sompong said. "Parliament should discuss and find solutions."
He added the opposition do not have enough seats to submit a motion, so government MPs are invited to join.
Prasert Jantararuangtong, secretary-general of Pheu Thai, said opposition MPs worked together to bail out students arrested.
Rames Rattanachaweng, spokesman for the Democrat Party, said the protesters showed disrespect towards the monarchy on Wednesday, referring to the Queen's motorcade incident. He said the mastermind behind it should come forward.
"The nation, religion and monarchy are the pillars of the country," Mr Rames said, adding those who break the law must face legal action, "otherwise the laws would lose their sanctity".
Thanathorn Juangroongruangkit, leader of the Progressive Movement group, yesterday on Facebook demanded the release of arrested demonstrators and denounced the use of the emergency decree as irrational and a form of power abuse.