By Prak Chan Thul
PHNOM PENH (Reuters) - Cambodian opposition leader Sam Rainsy on Monday delayed his return home from South Korea as tension comes to a head between his supporters and those of Prime Minister Hun Sen.
The Southeast Asian nation is still three years away from a general election, but acrimony between the two as they jockey for position is threatening to plunge the country back into political conflict.
A Cambodian court on Friday issued an arrest warrant related to an old defamation case for which Sam Rainsy had already received a royal pardon. The opposition party denounced the warrant as politically motivated.
Parliament on Monday stripped Sam Rainsy of the immunity that comes with his position in parliament.
Sam Rainsy had been due to arrive in Phnom Penh from South Korea on Monday. He would be arrested on arrival, said government spokesman Phay Siphan.
"There won't be any political compromise because he has lost all political status," Phay Siphan said.
Sam Rainsy said via Facebook that he had delayed his journey after talking to colleagues in Cambodia and a "number of international pro-democracy organizations" which suggested he arrive in daylight,"...and that I should also leave some time for diplomatic intervention to materialize with the objective of reaching a peaceful solution to the recent escalation of violence in Cambodia," he said.
He would fly to Cambodia "in the next few days", he added.
The warrant for his arrest was issued a day after self-styled strongman Hun Sen, in power for more than 30 years, threatened a lawsuit against Sam Rainsy for comments he made abroad about the election.
Sam Rainsy called on the international community to ensure that Hun Sen sticks to the election timetable and not use the deteriorating political situation to delay the vote.
The U.S. government on Monday said it was deeply concerned by Sam Rainsy's removal from the National Assembly and called for his reinstatement and the restoration of his parliamentary immunity.
"We also call on the government to revoke the arrest warrant issued against him on seven-year-old defamation charges and to allow him and other opposition parliamentarians to return to Cambodia without fear of arrest or persecution," State Department spokesman Mark Toner said in a statement.
Hun Sen has warned that an election victory for the opposition in 2018 would spark a return to civil war.
Robust economic growth, jobs creation and sustained peace for an impoverished country roiled by decades of civil war, including under Pol Pot's 1975-79 "killing fields" regime, have ensured Hun Sen's continued re-election, But experts say he now faces a strong challenge from a rejuvenated opposition popular among urban youth.
Sam Rainsy's Cambodia National Rescue Party ended a year-long parliamentary boycott after a deal in July 2014 with Hun Sen's long-ruling Cambodian People's Party that granted a series of concessions to the opposition party.
The deal fell apart after a year, when opposition party lawmakers were jailed for insurrection for their role in a protest.
(Additional reporting by Eric Walsh in Washington, D.C.; Writing by Simon Webb; Editing by Nick Macfie and Dan Grebler)