The CPP has used many slogans during its campaign, including perhaps the most ubiquitous: “A CPP Win Means the Whole of Cambodia Wins”.
A VOA Khmer investigation in April found evidence of large-scale troop movements in late 2017 from the highly militarized provinces of Oddar Meanchey and Preah Vihear to Siem Reap province.
Amnesty is also calling for detailed legislation and a comprehensive code of conduct on the use of force by law enforcement personnel.
Under the election laws of Cambodia, preventing someone from voting can carry a fine of up to about $5,000.
The only major challenger to Cambodian People's Party was disbanded last year.
Japan sent election monitors to Cambodian elections in 1993, 1998, 2003 and 2008, but Chief Cabinet Secretary Yoshihide Suga said it would not be doing so this time.
VOA Khmer's Aun Chhengpor recently sat down with Suos Yara, a CPP lawmaker, and spokesman, to talk about the ruling party’s definition of electoral democracy.
Cambodians will vote on Sunday in an election that has been criticized as a one-horse race with Prime Minister Hun Sen expected to win.
It's not clear to what extent such a ruling has a basis in Cambodian law.
The Interior Minister said Cambodians who were found to have taken part in the campaign would be fined up to 20 million riels (about $5,000).
The four tycoons identified by Global Witness are Mong Reththy, Ly Yong Phat, Try Pheap and Lao Meng Khin.