During the 2013–2014 Cambodian protests, Chhun led the first strike of around 300,000 garment workers that protested together with members of the opposition party Cambodia National Rescue Party (CNRP) in Phnom Penh. After the violent crackdown on the protests, Chhun was summoned for questioning together with Sam Rainsy and Kem Sokha. 5,000 people protested in front of the court building in their support. On January 21, Chhun was briefly arrested together with ten other activists. In November, he was, together with Yang Sophorn of the Cambodian Alliance of Trade Unions, prohibited from meeting other union leaders or attending demonstrations by Phnom Penh Municipal Court.