The renewed tensions between the ruling Cambodian People’s Party and opposition Cambodia National Rescue Party threaten to push Cambodia towards a “dangerous tipping point” if not resolved, the UN’s human rights envoy has said.

Her words came as CNRP president Sam Rainsy, a warrant issued for his arrest, left on a diplomatic mission to garner support in Europe.

“Any intensification of current events could bring Cambodia to a dangerous tipping point,” UN human rights rapporteur Rhona Smith said in a statement released yesterday.

Since the arrest warrant was issued, Rainsy has repeated the allegations that led to his defamation conviction – that Foreign Minister Hor Namhong was responsible for atrocities at a Khmer Rouge prison camp in the late 1970s.

He has also accused Prime Minister Hun Sen of working to destroy the opposition ahead of planned elections in 2017 and 2018.

Smith said that the increasingly bitter feud has gone hand-in-hand with an increase in rights abuses, including “incidences of violence; intimidation of individuals; and . . . offensive language in the political discourse”.

The rapporteur stressed that she would not interfere in Cambodian politics – an accusation levelled by the ruling party against previous holders of the post who criticised CPP actions – nor would she comment on the legal case against Rainsy.

But she added that it was of “great concern” that there were recently “multiple alleged violations of peaceful exercise of freedoms of opinion and expression, as well as the right to participate in political life”.

Already facing a two-year jail term if he returns to the Kingdom for the defamation ruling, Rainsy was summoned for questioning last week as an “accomplice” to forgery for allegedly allowing a “fake” version of a 1979 Cambodia and Vietnam border treaty to be published on his Facebook page.

And last month, three military officials were charged with the beating of two opposition lawmakers outside parliament after a protest against CNRP deputy president Kem Sokha.

Smith added that she had appealed privately to Hun Sen and Rainsy to return to the so-called “culture of dialogue”, a political detente that ended almost a year of stalemate following the 2013 general election.

Government spokesman Phay Siphan blamed the CNRP for the breakdown in the relationship, saying that the opposition leaders’ fiery anti-CPP rhetoric to supporters overseas had preached “rebellion”.

CNRP spokesman Yim Sovann said that the party was “deeply concerned with the deteriorating political environment” and would “continue to appeal to the CPP to ensure a calm environment conducive to politics”.