Thailand's Constitutional Court on Friday deferred ruling for a week on an incendiary charter amendment case that could lead to the dissolution of the ruling party.
The court heard evidence in a case centering on claims that plans by Prime Minister Yingluck Shinawatra's party to amend the constitution are a threat to the deeply-revered monarchy.
The complaint, brought by the opposition Democrats, has the potential to tear open the kingdom's bitter political rifts.
They also accuse Yingluck's Puea Thai party of seeking to redraw the country's charter to enable the return of her divisive brother Thaksin, who was ousted from power in a coup by royalist generals in 2006.
After two days of hearings Wasan Soypisudh, president of the Constitutional Court said it will deliver its ruling next week.
"The hearing today has finished," he said. "The court allows both sides to submit its closing statements in writing on Wednesday and the court will rule on Friday 13 (July)."
Puea Thai officials deny designs to undermine the monarchy.
"There is no action or intention to do anything as it (is) claimed in the complaint," Noppadon Pattama, Thaksin's legal advisor and a member of Yingluck's Puea Thai party told reporters on Thursday.
If court judges find that the amendment plans threaten the monarchy, it could lead to the dissolution of the party -- although would not necessitate Yingluck's departure -- risking a potential fresh wave of unrest in the volatile nation.
Political tensions in Thailand have spiralled since huge anti-Thaksin rallies helped topple the tycoon, who draws support from rural and working class "Red Shirts" but is reviled by the Bangkok-based elite and military.
Two pro-Thaksin premiers were forced from office in 2008 in judicial rulings, making way for the Democrats -- who have not won an election in 20 years -- to take power in a parliamentary vote.
Puea Thai swept to power last year on a wave of Thaksin support following deadly 2010 Red Shirt street protests.
Amending the constitution, which was drawn up under the post-coup junta in 2007, was a key plank of the party's election campaign.
Any suggestion of a return for Thaksin, who now lives in self-imposed exile to avoid a jail term for corruption, is hugely controversial in the deeply divided nation.
Democrats have stymied previous legislative attempts to engineer his return, while the monarchist Yellow Shirts took to the streets.
Last month Yingluck's party was forced to postpone a parliamentary vote on controversial "reconciliation" proposals strongly opposed by opposition MPs and the Yellow Shirts, who fear they will be used to grant an amnesty to Thaksin.