Parnthep Pourpangan, a spokesman for the People's Alliance for Democracy (PAD), which has been campaigning to bring down the government, told Al Jazeera that the verdict by the constitutional court was a victory for the people.
"We have been trying to protect the constitution, and the PPP have been trying to amend it to put forward their interests," he said.
Gothom Arya, a former electoral commissioner, said that the courts in Thailand have been "too involved in making political decisions".
"This is not good for the courts, this type of political manoeuvring does not reflect well on the insititutions, and it does provoke criticism and doubt as to how independent it can be," he said.
'Flights to resume'
Somkiat Pongpaiboon, a senior member of the PAD, said anti-government protestors will allow flights to resume from Bangkok's Suvarnabhumi international airport, after a blockade that has lasted for a week.
"As of this moment the PAD has allowed flights to take off and land immediately, both passenger and cargo flights," he said.
The PAD occupied Suvarnabhumi and the smaller Don Mueang domestic airport stranding 350,000 passengers and causing massive damage to the Thai economy.
Thailand's airport authority confirmed there was an agreement with protestors, saying flights may be able to resume if there are no "technical problems".
"We have reached an agreement with the PAD to start clearing protestors from the passenger zone to reopen Suvarnabhumi airport," said Vudhihaandhu Vichairatama, chairman of the board of Airports of Thailand.
"But how soon depends on technical issues. If there is no technical problems, the first flights would resume within 24 hours."
Party to regroup
The constitutional court also ordered the two other members of the ruling coalition - the Chart Thai party and the Machima Thipatai party - to be dissolved on Tuesday and its leaders banned from politics for five years.
However, minutes after the ruling, the PPP said members would regroup under a new name and propose a new prime minister.
|Anti-government protesters say they will meet to decide their next course of action [AFP]
Kudeb Saikrachang, a PPP spokesman, said the verdict had been expected and predetermined.
"We have known beforehand that this verdict would be announced, it is not a new development," he said.
"They [the courts] had a plan to destroy Thai Rak Thai party and now it is the PPP. The public are well aware of this.
"We want the people to understand the problems we are facing, and people will stand up, but this is another coup committed by the courts, and not by the military."
The Thai Rak Thai party, which was similarly dissolved by a military-appointed constitutional tribunal in May last year and its leaders banned from politics, regrouped as the PPP soon after.
The court had earlier changed venues for the hearing after hundreds of government supporters surrounded the building to try to stop the hearing.
Al Jazeera's Step Vaessen, reporting from outside the Administrative Court building where the case was moved to, described the situation outside the court as tense after the ruling.
"The people gathered here are very angry, and they believe a judicial coup has been committed against a democratically-elected government," she said.
"Some are heavily armed and are calling on people to fight this so-called judicial coup."
Hours before the court ruling, an anti-government protester was killed and 22 others were wounded in a bomb blast at the Don Muang airport.
Local Thai television Channel 7 said a grenade was fired from a flyover near the airport which has been occupied by the PAD.
The yellow-shirted PAD supporters have been trying for months to force Somchai out, accusing him of being a proxy for Thaksin Shinawatra, the premier ousted in a 2006 coup and the original target of the anti-government campaign.
Thaksin, who is Somchai's brother-in-law, is in exile after leaving the country to escape facing corruption charges.
So far, six people have been killed and scores injured in bomb attacks, clashes with police and street battles between government opponents and supporters.
Late on Monday, the PAD supporters began leaving the protest camp at Government House which they had occupied since late August. The move was aimed at consolidating their control of the Bangkok airports.