Demonstrators at Government House were unaware that a royal motorcade would pass their rally site and did not obstruct it as the government claimed when declaring the state of emergency, the Move Forward Party said on Thursday
The party that formed after the dissolution of the Future Forward Party said anti-government demonstrators had no intention of impeding the royal motorcade.
To the contrary, organisers had tried to avoid any royal motorcade route, as police had asked.
A government spokesman later asserted the state of emergency was necessary to prevent violence.
Spokesman Anucha Burapachaisri said the demonstration on Wednesday had affected many people. He said demonstrators approached the royal motorcade and offended the royal institution verbally.
Many people thought this was wrong, and the government had to declare a state of emergency to prevent a possible violent confrontation between different groups of Thai people, he said.
The Move Forward Party statement, on its Facebook page, said Prime Minister Prayut Chan-o-cha had claimed demonstrators obstructed a royal motorcade and cited it as a reason to declare a state of emergency early on Thursday morning, shortly before police dispersed the rally outside Government House.
A motorcade carrying Her Majesty the Queen and His Royal Highness Prince Dipangkorn Rasmijoti travelled on Phitsanulok Road, beside Government House, on Wednesday evening on the way to Wat Ratchaorasaram Ratchaworawihan for a royally sponsored robe-giving ceremony.
Demonstrators did not block the royal motorcade, the Move Forward statement said. They did not know the motorcade would pass the rally site, and had actually made way for it.
The opposition party condemned the delcaration of a state of emergency, and demanded the government revoked it right away.
The demonstrators rallied peacefully, without any weapons. The government had violated the rights of the people, who were dissatisfied with it, the statement said.
Thanathorn Juangroongruangkit, leader of the Progressive Movement group, demanded the release of the arrested demonstrators, and denounced the use of a state of emergency as irrational and an abuse of power.
The former leader of the disbanded Future Forward Party announced his group's stand via video on Facebook on Thursday morning.
He said arrested demonstrators had exercised their constitutional right of expression during their rally on Wednesday, and the government would have to release them.
Rally leaders had tried to relieve tension by announcing the suspension of their protest and told demonstrators to disperse at 6am on Friday.
"Therefore, the government had neither the legitimacy nor the necessity to declare a state of emergency and use force to end the rally," he said.
He demanded the government accept responsibility for any violence and unfair enforcement of the law against demonstrators.