Bangkok: Thailand`s ruling party faces the threat of dissolution in a touchpaper Constitutional Court ruling on Wednesday, amid fears the decision could inflame the country`s divisions as political rivals rally in Bangkok.
Hundreds of riot police were in and around the court ahead of its ruling 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 proposed changes would make the senate a fully elected body, returning parliament`s upper house to the structure it had before the 2006 coup that removed Thaksin and ushered in a period of political turmoil in the kingdom.
The nine judges began deliberating early Wednesday but were yet to reach a majority verdict, said an agency reporter at the court.
A verdict that the ruling Puea Thai party acted unconstitutionally in its push for the change could lead to its dissolution, with leading MPs facing five-year bans from politics.
This would risk fresh conflict in a nation that has been periodically rocked by bloody street rallies.
Yingluck called for calm Tuesday, urging pro- and anti-government groups not to "be emotional and clash with each other".
Experts said the constitutional court has a range of options, from allowing the amendment bill to become law, to declaring it unconstitutional and potentially bringing down the government.
"It is a stand-off, it is a confrontation. (The decision) is very crucial because it is a test of the Constitutional Court`s role," said analyst Thitinan Pongsudhirak, of Bangkok`s Chulalongkorn University.
He predicted the court would choose a middle option, preventing the amendment from becoming law as it stands but stopping short of a serious move against the ruling party.
Some 312 MPs and senators who supported the amendment have said they will not recognise the court verdict.
Judicial rulings have played an important role in politically turbulent Thailand.
Two pro-Thaksin premiers were forced from office in 2008 by such rulings, making way for the opposition Democrat Party, which is backed by the military and Bangkok`s elite, to take power in a parliamentary vote.
Thailand`s political temperature is already simmering after a controversial amnesty plan brought opposition rallies to Bangkok over fears it would have allowed Thaksin`s return from self-imposed exile.
The bill was killed by a senate vote last week, but the anti-government rallies have persisted, although numbers have reduced to a few thousand over recent days.
Around 20,000 pro-Thaksin "Red Shirts" have also gathered in the capital, vowing to oppose any decision that would remove another government linked to the ousted former premier.
Puea Thai swept to power in 2011 on a wave of support for Thaksin following deadly 2010 Red Shirt street protests, which were crushed in a bloody military crackdown under the then Democrat-led government.
Thaksin, a telecoms tycoon-turned-politician, has a strong electoral base, with ardent support from many in the country`s rural and working class for a raft of popular policies.
But he is loathed by the Bangkok elite and middle class, who accuse him of corruption.
Thitinan said the 2007 constitution aimed to rebalance the country`s power structures away from the executive, by shifting more authority to the judiciary and making around half the senate appointed.
"If you make the senate fully elected, the people behind the coup -- or who supported the military coup and the constitution -- will see it as a loss of power," he told the news agency.
He said they saw the constitution as "a last line of defence" against Thaksin and his allies.
"It`s a big fight but the constitution is just the arena."