Thailand's constitutional court ruled Friday the contentious constitutional amendment bill does not go against the constitution, relieving fears that an opposite verdict could throw the country into a new round of political turmoil.

The court rejected the petitioners' allegation that the bill breached the constitution. "There is no sufficient evidence to prove that the Pheu Thai Party is seeking to overthrow the constitutional monarchy," the verdict said.

The parliament can amend the constitution but cannot completely rewrite it, the verdict added.

The constitutional court advised the government to hold a referendum should it wish to rewrite the constitution. "The constitution was installed by the public. If the government wants to rewrite it, they should ask the public first," a judge told a press conference after delivering the verdict.

The ruling Pheu Thai Party has been pushing for the bill that revises Section 291 of the constitution to allow an assembly to rewrite the constitution. The bill was on its way to the third and final parliament reading when the constitutional court blocked the session scheduled on June 1.

The existing constitution was created after the 2006 military coup ousted former Prime Minister Thaksin Shinawatra, elder brother of the current Prime Minister Yingluck Shinawatra.

Analysts has warned of possibility of the ruling party being dissolved by the court if the bill was ruled unconstitutional. Two pro-Thaksin prime ministers were forced from office in 2008 by the court following huge street protests staged by anti-Thaksin demonstrators known as yellow-shirts.

In April 2010, Thaksin's supporters known as red-shirts occupied Bangkok's commercial district to demand early lower house elections. The rallies turned violent when the army tried to disperse protesters.

The Pheu Thai Party led by Yingluck swept to power in July 2011 elections.

"We accept the verdict as it is fair for everyone," said Tul Sitthisomwong, leader of an ally of opposition groups who call themselves "multi-colors".

Tida Thawornseth, chair of red shirts, said she disagrees with the ruling and does not believe the court has authority to consider petitions against parliament's efforts to revise the constitution.

Thepthai Senpong, spokesman for opposition Democrat Party, said the verdict is a win-win ruling acceptable to all parties. "It can ease political tension to a certain extent," he said.

Prime Minister Yingluck called on all parties to stay calm and accept the Constitutional Court's ruling before the verdict was handed down. She will go to Cambodia later Friday for the ASEAN-U. S. business forum.

"Any move should be within the legal framework. Don't resort to any violence. Eventually, (I) believe all sides should be able to talk to each other as we are all Thais," she said.

"The result is in line with expectation because the judges knew there would be a political mayhem if the verdict came out too bad for the government", said Chanetwallop Fhumthong, a political analyst at Chulalongkorn University.

But the verdict also served as a warning to the ruling party. " The judges are telling Pheu Thai -- we are watching you, be careful," he added.