Prime Minister Hun Sen has warned citizens and the opposition from sharing a “propaganda” leaflet urging Cambodians to boycott the upcoming elections on July 29.

“The propaganda calling people not to vote violates the country’s laws that are stated [in Article] 142 of the Law on Election of Members of the National Assembly,” he wrote on Facebook on Friday.

Article 142 says it is illegal to “deter” citizens from registering to vote or to cause “confusion resulting in the loss of confidence in the election”.

The leaflet, posted online by former opposition leader Sam Rainsy, is designed to discourage voters from taking part in what he characterises as “sham” election, after the Cambodia National Rescue Party was forcibly dissolved in November.

The premier’s condemnation echoes that of Som Sorida, deputy secretary-general of the National Election Committee (NEC), who on Wednesday claimed the leaflet violated the law.

Interior Ministry spokesman Khieu Sopheak said the Cambodian People’s Party would “fully cooperate” with the NEC in cases where they found people committing “wrongs”.

“We will confiscate even the printing house and bring people to the court,” he said, adding they would target “masterminds” of the leaflet plot, not small players like tuk-tuk drivers.

“In one nest there are many perpetrators, masterminds and [those] who provide the [printing] place . . . we strongly condemn them,” he said.

“Those people make incitement to make chaos in society and put the country in turmoil. [They are] demanding to bring the ghost of the CNRP back.”

Former CNRP President Sam Rainsy said the ruling party’s strong reaction showed they were “afraid of the prospects of a massive boycott of the election” and dismissed the claim the boycott was designed to cause chaos as “a ridiculous accusation”.

“Our boycott of the election is only a form of passive resistance in our peaceful fight for democracy,” he said in an email.

Rainsy added he did not want any CNRP supporters to be harmed and only he, as the “mastermind”, should be punished.

Kong Mas, the former head of the CNRP’s Svay Rieng provincial committee, who was due to stand as a lawmaker candidate in July, on Sunday said he still planned to print 100,000 copies of the offending leaflet.

“It is very unjust. The law is meaningless for the opposition parties and only has meaning for the ruling parties,” he said.

“Even though there is a threat to arrest me, intimidate me, [and] restrict my freedom of expression, I will do my activities in accordance with the Constitution,” he said, adding police and military officials had told him “prison is waiting for you”.

He said he would cancel his plans to print the leaflets if the CNRP were reinstated before the end of the party registration period on May 14.

But Hang Vitou, president of the Young Analysts Group, said he did not support encouraging CNRP supporters to share the leaflets as it left them open to incitement charges and arrests would make Cambodians “scared to go to vote”.

“It will make the political situation more tense. The arrest will make people more afraid and they will think the elections are under threat,” he said.

“The arrest of people will make the Cambodian People’s Party lose face.”

Additional reporting by Ananth Baliga