By Prak Chan Thul
PHNOM PENH (Reuters) - Cambodian Prime Minister Hun Sen said on Thursday a law was being amended to stop anyone convicted of an offence from running for office for five years, effectively barring his main rival from elections.
Opposition leader Sam Rainsy has been convicted of a series of defamation charges and has lived in exile in France since 2015 to avoid them. He rejects the charges as politically motivated.
Cambodia holds local elections in June and a general election next year. Opponents accuse Hun Sen of manoeuvring to try to keep his three-decade grip on power.
Hun Sen said work had begun on amendments to a 1998 law to ban politicians for five years if convicted by a court and dissolve a party if its leaders are convicted.
"A prisoner should never be a leader of a political party," Hun Sen told a graduation ceremony in a speech broadcast on national television.
Hun Sen's ruling Cambodian People's Party has a slim majority in parliament and could push through any legal changes. The prime minister did not say whether the changes to the law would bar a politician for previous offences.
Sam Rainsy said the law clearly targeted him and his Cambodia National Rescue Party, the only opposition party in the National Assembly.
But he believed it could still win the election.
"Whatever my position in the party, I remain the symbol and represent the spirit of resistance to the autocratic and corrupt Hun Sen regime," he said in an email to Reuters.
(Editing by Nick Macfie)