The case against Nuon Chea was plagued by political interference, undermined by biased and incompetent judges and riddled with legal and factual errors, according to the Khmer Rouge leader’s full appeal against a life sentence for crimes against humanity in August.

Released publicly yesterday, the 270-page document advances in detail 223 grounds for appeal against the verdict in Case 002/01, which held Chea and Khieu Samphan responsible for crimes committed following the Khmer Rouge’s capturing of Phnom Penh in 1975.

Chea’s lawyers take aim at the government’s “blatant and overt” interference in the trial to protect “the senior military officers who implemented the [Khmer Rouge’s] policies and today remain the highest ranking members of government”.

They assert the Cambodian government blocked access to witnesses and scuttled investigations as part of “an irrefutable pattern of conduct designed to diminish responsibility of former CPK officials such as [President of the National Assembly] Heng Samrin and [Prime Minister] Hun Sen at Nuon Chea’s expense”.

The defence calls for Samrin, Senator Ouk Bunchhoen and a third figure, whose name is redacted, to be summoned to testify as well as journalist Thet Sambath and filmmaker Rob Lemkin, who together investigated the genocide for the film Enemies of the People.

Chea’s team also accuses the judges of “deep bias”, calling their ruling “a post facto rationalisation of a long-held belief that the accused are morally repugnant and deserving of the harshest punishment”.

However, according to the defence, the tribunal’s biggest failure was finding that the Communist Party of Kampuchea was a highly organised, unified and pyramidal hierarchy, an assessment used to find Chea guilty for the deeds of lower ranking Khmer Rouge cadres.

Instead, they argue zone leaders were not subordinate to the party leadership, cadres at all levels had substantial autonomy and the organisation was splintered into “competing, equally strong, factions”.

Chea’s lawyers also state the seniority of his position of Communist Party of Kampuchea deputy secretary was “confused” with the nature and breadth of his tasks.

They contend he was neither in charge of military policy or internal discipline, nor was he the “ultimate decision maker” or known by the alias “brother number two”.

The appeal also asserts the tribunal lacked the jurisdiction and evidence to find there was a policy of forced marriage under the Khmer Rouge, or that Chea was actively involved in running the S-21 prison.

The defence also claims judges erred by the finding the most accurate estimate of people killed by the Khmer Rouge was between 1.5 and 2 million people, adding their attempts to examine variables that might of impacted the toll were blocked.

A government spokesman did not respond to phone calls and a text message last night.