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.
The leaders pointed to the One Belt, One Road initiative, a Chinese initiative that will connect the economies of Southeast Asia with large infrastructure projects.
Communication authorities ordered a 3-month suspension of the Tuoi Tre news website over allegations it ran a report that upset national unity
NEC has registered 107 domestic groups, which will be dominated by the Union of Youth Federations of Cambodia (UYFC), an organization led by Hun Many, the prime minister’s son and a lawmaker for the ruling Cambodian People’s Party (CPP).
Hang Puthea, NEC spokesman, said the messages were intended to remind political parties that they must comply with the law, adding that some political parties had already received fines for violations.