Hundreds of police surrounded Thailand's Constitutional Court Friday as the country braced for a crunch ruling that threatens to rip open the kingdom's bitter political divisions.
The court is set to rule on whether plans by Prime Minister Yingluck Shinawatra's party to amend the constitution -- drawn up under the military junta that deposed her divisive brother Thaksin -- are legal.
The opposition Democrats, which were swept out of power in a landslide election win for Yingluck last year, claim that the efforts to amend the constitution signal a threat to the deeply-revered monarchy.
A verdict against the ruling party could lead to its dissolution, risking fresh conflict in a nation that has been racked by bloody street rallies since huge protests helped topple Thaksin from power in 2006.
Yingluck -- who would not necessarily be removed from power even if her party is dissolved -- called for calm on the eve of the decision, urging people from all sides "not to use violence".
Several anti-Thaksin protesters gathered outside the court on Friday, while a faction of the rival "Red Shirts" -- mainly rural, working class supporters of the fugitive former premier -- also held a small rally near parliament.
National police spokesman Major General Piya Utayo said four companies -- around 600 officers were deployed in and around the court, with a further nine companies on standby nearby.
"The situation in and around the court is peaceful," he said.
Constitutional Court officials said eight judges -- two of whom were involved in drafting the constitution -- began deliberations on Friday morning.
Two pro-Thaksin premiers were forced from office in 2008 in judicial rulings, making way for the Democrats, who are backed by the military and Bangkok elite, to take power in a parliamentary vote.
Yingluck's Puea Thai party swept to power last year on a wave of Thaksin support following deadly 2010 Red Shirt street protests, promising to amend the constitution that was drawn up in 2007.
The party is trying to amend the section of Thailand's charter governing the process for changing the constitution in order to allow it to set up a redrafting committee and to put their recommendations to a referendum.
But the Democrats, who also fear the move could be used to open the way for Thaksin's return, allege the underlying motivation threatens Thailand's system of constitutional monarchy.
Observers said the court could decide to throw out the complaint, to rule against the party -- which denies any intent to undermine the royal family -- or to find a compromise agreement that would limit the extent of future revisions to the constitution.
Thailand expert Thitinan Pongsudhirak, of Chulalongkorn University in Bangkok, said there had been a "systematic effort to undermine and subvert democratic institutions" in recent years.
"In previous judicial dissolutions, the grounds were questionable but less bogus. This time... the verdict is rooted in presumptions about the future which has not happened," he said.
"There will be a severe backlash if we see yet another repeat of the usurpation of electoral rule and this time the court is in a much weaker position."