Sam Rainsy announced his resignation in a letter to senior members of his Cambodia National Rescue Party, or CNRP. Sam Rainsy has been in self-imposed exile since late 2015 to avoid a deferred two-year prison sentence for criminal defamation. He has been the target of several lawsuits by Hun Sen and his ruling Cambodian People's Party, or CPP. The opposition party already lacks momentum, and the move makes it even harder to see from where it will generate that momentum, he said. Hun Sen's grip on power seemed shaken in 2013's general election, when the Cambodia National Rescue Party mounted a strong challenge, winning 55 seats in the National Assembly and leaving Hun Sen's party with 68.

Source: ABC News February 11, 2017 11:53 UTC