The Cambodian People’s Party ran in the election without any major opposition. (ABC News: Liam Cochrane)
Ms Sochua is one of more than 100 opposition figures banned from politics in Cambodia.
She has been living in self imposed exile since her party was declared illegal last year, its leader jailed and its MPs banned from politics.
“Mr Hun Sen knew that he would lose these elections if we were to continue to exist,” she said of her party, which was gaining widespread popularity before its ban.
She said the Prime Minister’s solution was to “totally chop off the opposition”.
“We’re talking about human rights. Our people are not free to speak, to express themselves.”
The Cambodian Government said the election was orderly and transparent.
Video: Cambodian Information Minister bribes local media at ballot box.
Chinese State Councillor Wang Yi offered his congratulations for what he called a “smooth” election, in a statement released by China’s Foreign Ministry.
“China has always resolutely supported Cambodia’s efforts to protect its sovereignty, independence and stability, and opposes any foreign country interfering in Cambodia’s internal affairs,” the statement cited Mr Wang as saying.
The election result showed the Cambodian people’s “affirmation and trust” in the administration of the Cambodian People’s Party, Mr Wang said.
China is Cambodia’s most important diplomatic and economic backer, openly supporting Mr Hun Sen during his 33-year reign.
Mr Wang said China would continue to provide help to Cambodia to maintain stability and development.
Ms Sochua said while the people of Cambodia welcome investment and assistance from China, it needs to come with conditions that include human rights and democracy.
‘Australia didn’t take a strong stance, we were disappointed’
Cambodian Prime Minister Hun Sen says his party won all 125 parliamentary seats. (ABC News: Liam Cochrane)
Australia refrained from sending diplomats to monitor the Cambodian elections after threats, intimidation, bribery and the shutdown of independent media marred the lead-up to the vote.
“Australia has stated very strongly that the election was clearly not free and open, given the Cambodian Government’s actions in suppressing the activities of the opposition, the media and civil society in Cambodia,” Foreign Minister Julie Bishop said.
She said Australia would “engage with the Cambodian Government and make our concerns known” and “seek a response”.
Video: Julie Bishop says Cambodia's elections neither free nor open
But Ms Sochua said action is needed, not just words.
“It is time for a country like Australia to stop just saying ‘serious concern’, but to take steps,” she said.
“Do not accept the results and do not accept the next government in Cambodia. It’s not a legitimate government.”
Ms Sochua said the Cambodian opposition had been working with Australian state MPs, federal MPs and government representatives.
“There was only one message when we came before the elections — Mr Hun Sen must be given a clear signal from the Government of Australia that he cannot destroy democracy,” she said.
“But Australia didn’t take a strong stance. We were disappointed.”
She said Australia should have put more pressure on Mr Hun Sen to allow “a free, fair and democratic election”.
She urged the Government to consider visa sanctions and investment restrictions against high-ranking officials as well as economic sanctions.
The ruling Cambodian People’s Party said the election was orderly and transparent. (ABC News: Liam Cochrane)
“High-ranking officials in Cambodia are having money — using their dirty money — and investing in [Australia],” she said.
While Ms Bishop said Australia was “discussing with other like-minded nations including the US and others as to what would be an effective response” to accusations against the Cambodian Government, she refrained from stating what those options were, or if sanctions were among those options.
Ms Sochua urged the international community and the people of Cambodia to “band together” and ASEAN leaders to address human rights abuses by member states.
“If they … totally destroyed this culture of freedom and liberties, and it is allowed to go on with a dictator, it will move from Cambodia to the next country,” she said.