By Amy Sawitta Lefevre
BANGKOK (Reuters) - Thailand's ruling party said on Friday it would push ahead with plans to change the constitution after a court ruled that proposed amendments did not threaten the revered monarchy, a charge that might have led to the party's dissolution.
The decision means the government is not in danger of falling and should ease political tensions that have spiraled in Thailand over the past few days.
The Constitutional Court ruled that the government would need the go-ahead from a referendum before an elected assembly could rewrite the constitution, but it left the way open for parts to be changed without that and the ruling party said it might take that route.
"We are sad that the Thai people won't have a chance to change the charter through elected representatives but we are likely to proceed with changing the constitution article by article," Puea Thai party spokesman Prompong Nopparit said.
The government's "red shirt" supporters, who had been massing near parliament and had threatened protests if the ruling went against them, were jubilant.
"This is a historic moment for Thailand and we will continue to support the government," said Thida Thawornseth, leader of the red shirts' United Front for Democracy against Dictatorship.
The ruling was watched closely because it could have opened another front in Thailand's seven-year political divide between the royalist establishment and the mostly lower class red shirts.
Powerful royalists oppose any change to a constitution enacted under a military-backed government in 2007.
"The whole constitution cannot be changed but an amendment to separate articles in the current constitution can proceed ... If you want to change the whole constitution, you will have to ask the opinion of the Thai people first," said Nurak Mapraneet, one of the two judges who read out the verdict in court.
That verdict will allow the government time to work how out to proceed without giving either its supporters or opponents too much cause to protest.
"This is a ruling that keeps the balance between the opposition and the ruling party," said Siripan Nogsuan Sawasdee, associate professor in the political science faculty at Chulalongkorn University.
"I believe that the referendum will allow the whole charter to be amended because of the overwhelming support for this government," she said, adding, however, that the opposition Democrats should also be pleased because the process could not now be pushed through quickly.
King Bhumibol Adulyadej, 84, who has been in hospital for three years, suffered another bout of ill health overnight and has cancelled a trip out of Bangkok at the weekend. He is seen as a unifying figure and the news earlier on Friday added to the tension before the court case.
The government of Yingluck Shinawatra maintains its proposed changes are part of efforts to bring reconciliation to Thailand, altering a constitution seen by some as undemocratic.
Its opponents had argued the changes would threaten the constitutional monarchy and that one undeclared aim was to pave the way for former premier Thaksin Shinawatra to return from self-exile without serving time in jail for a graft conviction.
Thaksin is Yingluck's brother and is believed to be the real power behind her government, directing it from his villa in Dubai. A populist former telecoms billionaire, he is adored by the poor but reviled by the royalist establishment and military, which toppled him in a coup in 2006.
One article in the current constitution gives additional power to the judiciary and independent agencies that helped investigate corruption charges against him after he was deposed.
If it were amended, the legitimacy of action taken during the coup and the subsequent investigation could be questioned.
Kwanchai Praipana, a red shirt leader, told Reuters before the verdict the group was ready to gather at provincial town halls in the northeast, Thaksin's stronghold, if the court ruled against the charter change.
Thaksin's red shirts effectively paralyzed central Bangkok with a mass rally in April and May 2010 before a military crackdown ended it. At least 91 people died in the violence.
However, in some recent video-links to rallies, Thaksin has appeared more willing to compromise on the conditions for his return, telling his red shirt supporters to be patient since reconciliation would take time.
Hundreds of red shirts had gathered near parliament before the verdict, while around 200 people from a royalist group allied to the anti-Thaksin "yellow shirts" had gathered near the court.
(Writing by Alan Raybould; Editing by Raju Gopalakrishnan and Jonathan Thatcher)