Opposition lawmakers said they will demand that Prime Minister Hun Sen halt ongoing efforts to demarcate Cambodia’s border with Vietnam until after the 2018 election to guarantee a consensus on the controversial boundary. This came as the Ministry of Foreign Affairs yesterday again moved to reinforce its stance against Vietnamese encroachment.

News of the request also came as authorities confirmed a local border police chief in Ratanakkiri province’s O’Yadav district had been removed for allowing the Vietnamese to build at least nine irrigation ponds inside the yet-to-be delineated “white” zone near Pak Nhai commune’s Lom village.

The ponds, initially discovered by rights group Adhoc and publicised by Cambodia National Rescue Party lawmakers, have sparked a recent flare-up in the long-running and politically sensitive border dispute.

On Friday, the Ministry of Foreign Affairs issued a rare public protest to the Vietnamese Embassy in Phnom Penh demanding the borderline be respected, which it followed up two days later when more ponds were discovered.

Yesterday, in a letter to the National Assembly responding to CNRP concerns, Foreign Minister Hor Namhong said that since 2013, the ministry and the Cambodian Embassy in Hanoi had protested eight times to Vietnam over territorial violations.

Although welcoming the government’s tougher stance, CNRP lawmakers continue to question whether ongoing demarcation is based on the “wrong” map they claim was drawn up by Vietnam for controversial treaties inked in 1985 and 2005, rather than boundaries set forth by the UN map and former King Norodom Sihanouk in the 1960s.

Accusing the government of ceding land to Vietnam in Takeo, Svay Rieng and Tbong Khmum provinces, CNRP lawmaker Um Sam An said no more border posts should be planted until after the national election, when leaders from both parties could review the process.

“There is still controversy about the map.… Post-election, let both [parties’] leaders talk about planting the border posts with Vietnam to avoid more loss of land,” he said, adding a joint letter would be sent to the prime minister next week.

Responding, Cambodian People Party’s spokesman Sok Eysan yesterday said 70 to 80 per cent of the demarcation process had taken place under the government’s “clear plan”, although it was unclear when it would be finished.

He declined to comment on postponing demarcation until seeing the CNRP request.

Previous reports by the government – which has long been reluctant to publicly address long-running border tensions with Vietnam – have stated that, overall, 375 posts will be planted along 1,270 kilometres of shared border.

Political analyst Ou Virak said the recent condemnation of Vietnam – including the deportation of more than 500 Vietnamese illegal immigrants in the past six months – looked to be an attempt to counter the CNRP’s populist appeal on the issue.

“It’s always been very difficult for the CPP to shake off the image of a party that was installed by communist Vietnam in the ’80s,” Virak said. “I think the only way to do that is to address some of the legitimate issues of immigration and border encroachment.”

Although agreeing, Markus Karbaum, an independent consultant specialising in Cambodia, said the shift could also be explained by an ongoing process of “emancipation” from Vietnam’s “hegemonic foreign policy” towards the Kingdom, thanks to growing Chinese support.

“The Hanoi government has definitively forfeited its position as the main backer of regime in Phnom Penh,” Karbaum said.

However, Southeast Asia defence expert Carl Thayer, professor emeritus at the University of New South Wales in Australia, said “local factors” were likely behind the flare-up.

He dismissed the notion that tensions linked to geopolitics, including Cambodia’s pro-China stance on the South China Sea dispute with Vietnam, might be the drivers.

Meanwhile, Rattanakkiri Deputy Governor Nhem Sam Oeurn yesterday confirmed Lom village border police chief Rocham Chib was transferred from his post to the provincial police station and suspended two weeks ago for allowing the ponds to be built.

Despite several meetings and an official request, the Vietnamese had not refilled the ponds, he added.

ADDITIONAL REPORTING SHAUN TURTON