A week after opposition leader Kem Sokha said his party would no longer appeal to anti-Vietnamese sentiments in its campaigns, two prominent opposition officials said on Saturday the party would demand the return of southern Vietnam to Cambodia if it wins power next year.

Speaking at Phnom Penh’s Wat Chas at an event to mark France’s June 1949 transfer to Vietnam of its Cochinchina colony, which many still consider Cambodian territory, Prince Sisowath Thomico and lawmaker Ho Vann said the party would not shy from the issue.

“Kampuchea Krom is part of Cambodia, and we have the right to demand our own territory without receiving pressure from anyone,” Thomico said, using a term that means “Lower Cambodia”. “We have to organise a plan to campaign to demand Kampuchea Krom back.”

“In 2018, a government led by the Cambodia National Rescue Party will organise a plan using a diplomatic path to demand Kampuchea Krom come back together with Cambodia,” the prince said. “This is a point that I commit to and promise the nation.”

Thomico, who is also the chair of the foreign affairs subcommittee in the CNRP’s standing committee, said that it was unfair for “foreigners” to pressure the CNRP to avoid talking about Cambodia’s historical enemy or illegal immigration in its campaigns. “We were the victims, and we are the victims once again, because when we demand the territory of Kampuchea Krom back, when we demand to divide up the borderline, they accuse us of racism,” the prince said, describing the opposition’s positions as not unusual.

“The US has a goal to build a fence of thousands of kilometres across America from the Pacific Ocean to the Atlantic Ocean, to stop immigrants coming up from the south of America,” Thomico said. “So may I now please ask: Is the US being racist?

“All we are doing as Cambodians is demanding our rights to resolve the illegal immigration problem, and demanding our rights to place border posts, and they accuse us of being racist. This is a great injustice.”

Sokha was invited to Saturday’s commemoration but was instead in Takeo continuing a national speech tour he started after the June 4 commune elections. CNRP lawmakers Ho Vann, Long Ry, Kong Saphea and Sok Oumsea attended the event and sat on stage.

Vann, a member of the CNRP’s standing committee and vice chair of its disciplinary committee, said in his speech that the CNRP and the Khmer Kampuchea Krom community, which is led by former opposition Senator Thach Setha, shared many similar goals.

“Let me take just two important points. The first is that all Khmer Loeu, Khmer Kandal and Khmer Krom – all Khmer – have to have the goal of, firstly, asking for the territory of Kampuchea Krom to be given autonomy,” Vann said, using terms for ethnic Khmer living in Thailand, Cambodia and Vietnam, respectively. “I am not from Kampuchea Krom, but I stand absolutely united with my brothers and sisters in Kampuchea Krom in their demands on this first request.”

Vann explained that the CNRP wanted self-government for Khmers in southern Vietnam so that Cambodia’s religion, writing system and culture could be protected – but he said the opposition party could not do much if it was not in government.

“The second request is what has been raised by others about demanding Kampuchea Krom back,” Vann said. “It doesn’t matter what we organise – the most important people are the group in government, and the government showing its face to find independence for our nation to take back Kampuchea Krom.

“We go into the future thinking about this.”Reached by telephone, opposition spokesman Yim Sovann, who did not attend Saturday’s event, declined to comment either on what the CNRP’s policy is on the sovereignty over Kampuchea Krom or on the remarks made by the two party officials on Saturday.

“Anyone who spoke, please speak to them. They are not speaking on behalf of the party,” Sovann said, before also declining to discuss the CNRP’s position to avoid campaigning on Vietnam. “I have no more comment to add to what Kem Sokha said.”

CNRP lawmakers (L-R) Sok Oumsea, Kong Saphea, Long Ry, and Ho Vann seated at a Wat Chas ceremony on Saturday to mark the 68th anniversary of France's transfer of its Cochinchina colony to Vietnam.Alex Willemyns

At the 2014 Kampuchea Krom event, Sokha himself accused Vietnam of having “used the CPP and Hun Sen to eliminate the Khmer race, tradition and culture”, and of orchestrating the 2010 Koh Pich stampede, which killed 347 people, as a pretext to keep cancelling Cambodia’s annual Water Festival.

However, in an interview a week before Saturday’s ceremony, he said that the opposition was trying to avoid the divisive issue as the 2018 national election nears. Two former CNRP lawmakers are already in jail over comments they made about the CPP allegedly ceding territory to Vietnam.

“The CNRP has become a party that is preparing to lead the country, so there is no need to talk about these issues that just bring some popularity and also bring disputes and tension,” Sokha said on June 17. “It will create anger. It’s a hot issue, and we try to avoid it.”

Saturday’s event came only three days after Hun Sen, who has chafed at being called Hanoi’s “puppet” ever since he was installed by Vietnam as prime minister in 1985, held his own ceremony to mark 40 years since he defected to Vietnam from the Khmer Rouge.

Vietnam’s role in Cambodia has long been the major dividing line on the country’s political scene, with the ruling CPP to this day remaining largely led by figures who came to power under Vietnam’s decade-long occupation after the 1979 overthrow of Pol Pot.

The CNRP, meanwhile, is led by figures associated with the armed resistance that fought a civil war against the regime in the 1980s. Former CNRP leader Sam Rainsy was a founding member of Prince Norodom Sihanouk’s Funcinpec, while Sokha’s roots lie in former Prime Minister Son Sann’s allied Khmer People’s National Liberation Front.

Son Sann’s son, Son Soubert, also spoke briefly on Saturday at Wat Chas. The event was presided over by Princess Sisowath Pongneary Monipong, who attended the commemoration, as she does each year, as a representative of King Norodom Sihamoni.

Astrid Noren-Nilsson, a Swedish political scientist and author of Cambodia’s Second Kingdom, Nation, Imagination, and Democracy, said the princess’s presence at the event each year as a representative of the King was not casual.

“According to Thach Setha, only King Sihanouk supported the first celebration in 2000, and originally allowed it to be held on the property of the Royal Palace,” Noren-Nilsson said, with the royal family long chafing at the loss of land to Vietnam. “It has been important for the Kampuchea Krom activists to show that Sihanouk, as father of national independence, supported their cause,” she said.

Yet Noren-Nilsson said that even if any attempts by the CNRP to now move past the Vietnam issue were “sure to make the opposition appear more legitimate in international circles” as national elections approach, the situation on the ground was different.

“Even if the role of Vietnam were not to be discussed openly, it is too central to the opposition’s analysis of Cambodia’s political and economic situation to be tossed aside: Vietnamese influence is believed to condition every single policy area,” she said.

David Chandler, an eminent Cambodia historian who wrote the comprehensive A History of Cambodia, said that any CNRP campaigning on sovereignty over Kampuchea Krom was in any case ultimately moot and only useful for appealing to anti-Vietnamese sentiments.

“There is no way Vietnam is going to give up a square centimetre of its territory. The Khmer Krom are a minority in what was once Cochinchina,” Chandler said, adding that he doubted that meant the opposition would take Sokha’s lead and focus on other issues.

“Sadly, no,” he said. “It gets people excited, and it postpones the CNRP coming up with any concrete proposals about altering Cambodia’s governance.”