phnom penh cambodia government raise possibility main opposition party could rule elections replace leader kem sokha charge treason opposition cambodia national rescue party cnrp say replace leader comment reinforce fear prime minister hun sen plan cripple next year elections arrest kem sokha sunday draw western condemnation mark escalation crackdown critics hun sen rule 30 years could face possibly tough electoral challenge cnrp next year appoint act president government spokesman phay siphan tell reuters tuesday comply law exist right political activity ... choice choice kem sokha daughter kem monovithya also party official say party would appoint new leader kem sokha name february predecessor resign fear party would ban stay rule party drop divide-and-conquer plan say opposition officials accuse hun sen try weaken destroy party ahead election well june local elections nonetheless come well behind hun sen cambodia people party hun sen one asia long serve rulers say wednesday could arrest act treason reinforce need stay office decide continue work less 10 years tell garment factory workers jab finger air emphasis kem sokha become leader opposition veteran sam rainsy resign new law forbid party leader find guilty crime sam rainsy flee exile avoid defamation conviction say political cambodian law say political party 90 days replace president die resign convict offence western countries condemn arrest kem sokha crackdown critics hun sen include independent media care people outside phay siphan say care national security belong anyone china hun sen close ally voice support cambodia step ensure security kem sokha formally charge treason tuesday lawyers dismiss evidence present far video publicly available since 2013 tell supporters get support advice americans campaign win elections government rule cpp manufacture treason charge kem sokha political purpose aim try knock political opposition ring 2018 electoral contest even begin say phil robertson deputy asia director new york-based human right watch exclusive cambodia say opposition party could bar election