The prince and his wife, Ouk Phalla, 39, were traveling to meet supporters in the southwestern province on Sunday morning.
Some 8.4 million Cambodians were registered to vote in the election, according to the latest voter lists.
The Council also urged the release of Kem Sokha, the CNRP president who was jailed in September on treason charges for his supposed role in an alleged plot to overthrow Hun Sen.
The move came after the U.S. State Department and Senate repeatedly warned that punitive measures would be forthcoming if Cambodia did not reverse recent anti-democratic actions.
Cambodian security guards claim they were involuntary added to Facebook Messenger Group.
Chinese Defense Minister Wei Fenghe is due to meet Prime Minister Hun Sen during his five-day visit, which ends on Wednesday.
The party says it is concerned with drawing the ire of the ruling Cambodian People’s Party, whose leadership has been accused of being behind the killing.
Pak Lay project notification follows dire findings of MRC study.
You Hok Kry, Funcinpec vice president, said at Phalla’s funeral that the prince had been involved in three car accidents since 2015 which he found “really suspicious”.
James Ricketson says authorities have not given the defense any of the evidence collected against him.
Prime Minister Hun Sen and other senior ruling Cambodian People’s Party figures have labeled those participating in the boycott as “traitors”.
Recently, hundreds of villagers involved in land disputes have traveled to Phnom Penh to lobby the government ahead of the election.