As a result of the charges, Sam Rainsy has been stripped of his parliamentary immunity.
The Anti-Corruption Unit have been criticized as toothless to attack the pervasive corruption across the government.
The Appeals Court said Wednesday that the two villagers could be released with time served.
Cambodia's workers say they have come under increased pressure from a rising cost of living.
Ros Sokhet, was sentenced to two years in prison after he sent text messages to a famous news anchor that were deemed threatening.
The Anti-Corrupiton Unit is preparing to examine some 90 complaints of graft by tax officials from the Ministry of Finance.
Phao Sak, 26, was in serious condition in Calmette hospital in Phnom Penh following the assault.
Hun Sen said Wednesday that if the court complaints went forward, the strikes would continue.
The 12 years are added to a two-year sentence Sam Rainsy is already facing for uprooting markers along the Vietnamese border last year.