The European Union has said it cannot support the vote after the country dissolved the main opposition party. The EU follows a similar move taken by the United States.
The European Union announced on Tuesday that it was suspending funding for Cambodia's 2018 national election after the government dissolved the main opposition party.
The Cambodia National Rescue Party (CNRP) was disbanded last month by the country's Supreme Court after longtime Prime Minister Hun Sun announced the arrest of opposition leader and rights activist Kem Sohka for treason.
Hun Sen has repeatedly accused Kem Sokha of colluding with the United States to overthrow the government, but Kem Sokha has maintained that his detention was meant to get him out of the way before the National Assembly elections.
"An electoral process from which the main opposition party has been arbitrarily excluded cannot be seen as legitimate," the EU stated in a letter seen by Reuters news agency.
"Under these circumstances, the European Union does not believe there is a possibilty of a credible electoral process."
According to the Phnom Penh Post, the EU had pleged 10 million euros ($11.7 million) to support fair and peaceful elections across the country, including the donation of election equipment. The EU becomes the second international partner to pull its aid, after the United States.
The EU's move was criticized by National Election Commission (NEC) deputy leader Som Sorida for mixing politics with election assistance.
However, Russia, South Korea, China and Japan are still offering their support for the country's parliamentary vote set for next July.
es/jm (Reuters, EFE)