Bangkok. Hundreds of protesters gathered in Thailand’s capital on Saturday, demanding the resignation of Prime Minister Paetongtarn Shinawatra, escalating a brewing political crisis triggered by a leaked phone call with former Cambodian Prime Minister Hun Sen.

Paetongtarn faces growing dissatisfaction over her handling of a recent border dispute with Cambodia that led to an armed confrontation on May 28, killing one Cambodian soldier in a contested area. The clash has sparked multiple investigations that could result in her removal.

Protesters, waving national flags and holding signs, occupied streets around Bangkok’s Victory Monument, where a large stage was set up for speakers addressing the crowd. Organizers said the demonstration was a show of “love for the country” amid the deepening border tensions.

Many of the protest leaders are familiar faces from the Yellow Shirt movement, whose members are known for wearing yellow to signify loyalty to the monarchy. They have long opposed Paetongtarn’s father, former Prime Minister Thaksin Shinawatra, and previously led rallies that turned violent and paved the way for military coups in 2006 and 2014, which ousted the elected governments of Thaksin and Paetongtarn’s aunt, former Prime Minister Yingluck Shinawatra.

The leaked phone call fueling the outrage involved Paetongtarn telling Hun Sen, now the president of Cambodia’s Senate and a longtime friend of her father, not to listen to “an opponent” in Thailand, believed to refer to the regional Thai army commander who publicly criticized Cambodia over the border clash.

On Saturday, Hun Sen vowed to defend Cambodian territory from foreign invaders, condemning what he called an attack by Thai forces last month. Speaking at a 74th anniversary celebration of his Cambodian People’s Party in Phnom Penh, Hun Sen said the Thai military’s actions inside Cambodian territory were a serious violation of sovereignty.

“Cambodia has suffered from foreign invasion, war, and genocide, but now we have risen to stand equally with other nations,” Hun Sen told thousands of supporters, emphasizing the need for peace, friendship, and cooperation.

Territorial disputes between Thailand and Cambodia have a long history. Tensions persist over a 1962 International Court of Justice ruling awarding Cambodia the territory surrounding the historic Preah Vihear temple, with sporadic clashes erupting as recently as 2011. The court reaffirmed its ruling in 2013 when Yingluck was prime minister.

The scandal has fractured Paetongtarn’s fragile coalition government, costing her Pheu Thai Party its largest partner, the Bhumjaithai Party. Tensions had already emerged over reports that Bhumjaithai would lose control of the powerful Interior Ministry, and several of its leaders are under investigation for allegedly rigging last year’s Senate election.

The departure of Bhumjaithai leaves the 10-party coalition with 255 seats in the 500-seat House, maintaining a slim majority.

Paetongtarn also faces investigations by Thailand’s Constitutional Court and the national anti-corruption agency, both of which could result in her removal. The secretary-general of the National Anti-Corruption Commission confirmed this week that the agency is investigating Paetongtarn for a serious breach of ethics over the phone call but did not indicate a timeline for a decision.

Reports indicate the Constitutional Court could suspend Paetongtarn pending the investigation and may decide as early as next week whether to take up the case. Paetongtarn said Tuesday she is prepared to defend herself.

“It was clear from the phone call that I had nothing to gain, and I did not cause any damage to the country,” she said.

Thailand’s courts, especially the Constitutional Court, are widely seen as strongholds of the royalist establishment, frequently used alongside nominally independent agencies like the Election Commission to challenge or remove political opponents. The court last year removed Paetongtarn’s predecessor from the Pheu Thai Party over a similar ethics breach.