The two appeared before the Court of Appeals on Wednesday, withdrawing their appeal without explanation.
Chan Cheng and a party lawyer are accused of helping a party activist, Meas Peng, wanted for questioning in a land dispute.
The National Assembly, which is dominated by the ruling Cambodian People’s Party, voted to suspend Chan Cheng’s immunity last week.
Foreign Minister Hor Namhong told reporters that Cambodia would work toward regional integration in 2015.
Kim died of a heart attack, and while it appears Kim Jong-un will succeed him, there are questions over an internal political crisis.
Civil society leaders have said they would need at least a month to properly review the law.
Cambodia maintains friendly relations with the reclusive nation, which were forged by the former king, Norodom Sihanouk.
Nuon Chea, Pol Pot’s former lieutenant, told the court that Norodom Sihanouk had visited members of the Khmer Rouge for a week in 1973.
The first version was sent back to them from the Council of Minsters, following widespread criticism from the international community.
Pung Chhiv Kek, founder of the rights group Licadho, said Cambodia was now sliding backwards in its adherence to human rights norms.
When the Khmer Rouge took over Phnom Penh, on April 17, 1975, they began marching people out of the city almost immediately.
Ieng Thirith would then be re-evaluated within six months to determine whether she is fit to stand trial, the court said.