In The GRUNK
After the Cambodian coup of 1970 in which Sihanouk was ousted by Lon Nol, Yuon became a part of the GRUNK, the Beijing-based government-in-exile that was formed as a coalition between Sihanouk and the communists. Yuon was made Minister for Cooperatives, and caused serious rifts between himself and other members of the Khmer Rouge leadership by protesting at the speed with which collectivisation was being carried out in the 'liberated' areas. As early as 1970, he had publicly criticised Pol Pot, complaining that the Party was using his name as a "screen" by making him a "puppet minister". He also argued against the abolition of markets, allegedly warning Pol Pot and Nuon Chea "If you go on like this, I give your regime three years. Then it will collapse".
Yuon's outspoken criticisms of Khmer Rouge policy led to him spending a brief period in a 're-education' camp, K6, in 1974. However his personal friendship with Pol Pot and his general popularity, both with the peasantry and with expatriate Cambodian intellectuals, led to a period of reinstatement in the Party leadership during 1975.
Read more about this topic: Hou Yuon