Thailand's Constitutional Court defused the country's latest political crisis on Friday, dismissing a controversial case that alleged ruling party lawmakers trying to amend the constitution were plotting to overthrow the monarchy.

Had the court sustained the complaint, there were fears it could have ordered the party of Prime Minister Yingluck Shinawatra dissolved, a move that many feared would provoke mass street protests and possible violence.

The case involved an attempt by lawmakers from Yingluck's Pheu Thai party to establish a drafting committee to amend the constitution, which they see as undemocratic because it was created in the wake of a 2006 military coup.

In reading the compromise verdict, judge Nurak Marpraneet said the 2007 charter could be amended section by section, though it could not be entirely rewritten.

Nurak then said "there are not enough facts to show" that the charter amendment aimed to topple the constitutional monarchy.

"What the complainants indicated in the petition was merely speculation," he said.

The complex legal case was the latest convulsion of a sometimes-violent tug-of-war between allies and adversaries of the exiled billionaire Thaksin Shinawatra, the populist former prime minister who was overthrown six years ago. It is also marks one of the biggest tests yet of the stability of the government led by Yingluck, Thaksin's sister, which rose to power 12 months ago in a landslide election that was widely viewed as a referendum on Thaksin's rule.

The court is closely identified with a conservative, elite establishment that has long seen Thaksin's popularity as a threat to its own power and influence. There are complaints the court wields too much power and that its rulings serve political aims. The court's members have removed two Thaksin-allied prime ministers in the last four years, and they have dissolved major political parties and banned top politicians from politics.

The case began last week when the court called 15 witnesses to argue both sides for two days.

The current charter was drafted in 2007, one year after the coup, by an interim, military-backed government. It was approved by Thai voters, but they had no real option if they wished to see constitutional rule and electoral democracy quickly restored.

In response to Thaksin's substantial mandate, the new constitution sought to limit the power of elected politicians, changing the Senate from an all-elected body back to a partly appointed one. It also strengthened the power of independent state agencies and the judiciary.

"This is a system designed by the coup-makers," said Chaturon Chaisang, a senior Pheu Thai member.

The Constitutional Court in particular is enormously powerful, entrusted with the ability "to remove the prime minster, dissolve parties they don't like - to overthrow governments they don't like," he said. " That's the problem. That's not democracy ... that's why" the constitution needs to be amended.

Speaking before the ruling, Wiratana Kalayasiri, a lawmaker from the opposition Democrat party and one of the complainants in the case, said the issue was that proponents of constitutional change want to redraft the entire document, although the ruling party has not made their intentions clear either way. "The charter only allows the constitution to be amended, but not totally rewritten," he said.

Yingluck's party has so far said it only wants to set up a 99-member drafting, and the current case involves changing one amendment that would enable them to begin that process.

That the court agreed even to hear the case has surprised some analysts, who say it had no jurisdiction to do so.

"It's not really sensible to make legal sense of these proceedings," said Verapat Pariyawong, an independent Harvard-educated lawyer. "You have to look at this as a political phenomenon."

Opponents of changing the charter are mostly Thaksin's critics, who fear it could help him return to power. The former premier, a deeply divisive figure despite his popularity, now lives in exile in Dubai to avoid a 2008 corruption conviction he says was politically motivated.

Clashes between the two sides have shaken the country's stability repeatedly. In 2008, Thaksin's opponents seized the prime minister's offices for three months and Bangkok's two airports for a week. In 2010, Thaksin's supporters held street demonstrations that degenerated into violence and clashes with the military that left more than 90 people dead and almost 2,000 injured.