PHNOM PENH -- With Prime Minister Hun Sen set to cruise to a landslide victory in Cambodia's general election on Sunday, the preservation of his dynasty, and the ever-increasing importance of his three sons, is under the limelight.

Despite 20 parties standing in the ballot, Hun Sen is expected to clinch a comfortable victory after the only realistic threat to his 33-year rule, the Cambodia National Rescue Party, was outlawed in an internationally condemned move last November. Its leader, Kem Sokha, was jailed on widely discredited claims he was stirring up a revolution backed by the U.S.

With the Cambodian People's Party looking forward to another five years in power, analysts expect Hun Sen's three sons, Hun Manet, Hun Manith and Hun Many, to be elevated to higher offices as their father seeks to hang on to power.

"There's no doubt in my mind the stage is set for ever more power in their hands. The reason is simple: The very survival of the Hun clan is at stake," said Sophal Ear, associate professor of diplomacy and world affairs at Occidental College in Los Angeles.

The wheels for their ascension have long been set in motion. Hun Manet, the 40-year-old eldest son who was educated at the U.S. Military Academy, was this month made a four-star general and appointed as deputy commander of the army. Hun Manith leads a powerful intelligence department, while Hun Many is a lawmaker and runs the party's influential youth wing.

Hun Manet, who declined to be interviewed, has long been touted as successor to his father. Yet, he has always stopped short of declaring any desire to become prime minister, answering "not no, not yes," when asked on Australian TV in 2015 if he would assume the mantle.

A few months later, Hun Many said in a radio interview that he aspired to be prime minister, but added that this should be the goal of all Cambodian youths.

The ruling party is not as monolithic as may appear on the surface -- plenty within are vying for influence and power. There has long been speculation of factional rivalries with Hun Sen on one side, and Interior Minister Sar Kheng and Senate President Say Chhum on the other, both of whom are perceived by the opposition of being more reform-minded. The CPP has always publicly refuted any suggestion of internal strife.

"Power struggles are unlikely to spill into the open," said Sebastian Strangio, a journalist and political analyst who has covered Cambodia extensively. "History suggests that the CPP, when faced with outside pressure (as it is now), will close ranks. Survival comes first."

After CPP President Chea Sim died in 2015 -- who was also widely seen as a factional rival of Hun Sen -- both Sar Kheng and Say Chhum were bestowed with the honorific "Samdech." The title is generally saved for royalty and monks with the exception of four other civilian leaders, including Hun Sen and his wife Bun Rany. Some observers perceived the move as a token gesture to promote unity within the party.

Say Chhum's son, Say Sam Al, has already been made minister of environment, and there will be more offspring of the party's upper echelons looking to fill high-level positions in years to come.

Strangio said the premier would continue to advance his sons through the political and military ranks, while keeping an eye on internal opposition.

'"Governance in this context has consisted of anticipating and neutralizing (or buying off) potential threats, and constantly renewing the loyalty of key political, business, and military elites," Strangio said, citing this as a reason why promises of "reform" so frequently come to nothing as any change true reform would likely alienate key allies.

"This balancing and shuffling will continue beyond the election, and anyone suspected of divided loyalties will undoubtedly be demoted or sidelined," said Strangio. Purges are not uncommon in Cambodian history, and were particularly brutal during the rule of the Khmer Rouge in the late 1970s.

But Astrid Noren-Nilsson, an associate senior lecturer at Sweden's Lund University specializing in Cambodian politics, said she took Hun Sen on his word when he recently vowed to remain in power for another 10 years to "maintain stability."

"I don't see him pulling a Sihanouk-style 'abdication' to secure a power transfer to one of his sons, at least not anytime soon," she said, in reference to the former king who stepped down in 2004, eventually making way for his son Norodom Sihamoni.

The question of how the Cambodian public perceive Hun Manet is difficult to gauge. While he has made some effort to distance himself from his father, he has generally toed the party line and backed Hun Sen on big issues including the arrest of Kem Sokha.

The ascension of the prime minister's more reserved and affable son could be welcomed by some Cambodians, Sophal Ear said. But a continued penalization of the ruling party's opponents would result in him being shunned by those seeking genuine change.

"Unfortunately the honeymoon will be short-lived if the ruthless crackdown on freedoms continues. It's clear there's no light between father and son," he said. "The line from Animal Farm [a novel by George Orwell] applies: 'All animals are equal, but some animals are more equal than others.'"