Cambodia's Senate has approved a law on creating a tribunal of judges to try the leaders of the murderous Khmer Rouge regime of the 1970s.
The approval cleared yet another hurdle in bringing to justice the perpetrators of the atrocities committed during the 1975-79 rule of the Maoist movement.
An estimated 1.7 million Cambodians were executed or died of starvation or disease during the Khmer Rouge rule.
The law was approved by the lower house of Parliament, the National Assembly, earlier this month and now needs the approval of the Constitutional Council and King Norodom Sihanouk.
The Government and the United Nations then must sign an agreement on details for the tribunal to convene.
The tribunal is not expected to conduct mass trials but only try those "most responsible" for the atrocities committed under the Khmer Rouge leadership of Pol Pot.
Prime Minister Hun Sen has said he expects the tribunal to start work this year.
Mr Hun Sen says the Government was ready to apprehend anyone the court indicts, as the legislation demands, but has cautioned against prosecution of the late Pol Pot's former foreign minister and brother-in-law, Ieng Sary, saying that could lead to war.
The Khmer Rouge, which strove to create an agrarian utopia through terror, was ousted from power in 1979 by a Vietnamese invasion, but survived as a rebel group along the Cambodian border with Thailand until 1998.
Ieng Sary led the defection of some 10,000 troops and civilians, in 1996, which crippled the movement. He was given immunity and now lives freely along with other top Khmer Rouge in their former stronghold in northwestern Cambodia.
Only two senior Khmer Rouge figures are in custody: longtime military leader Ta Mok and Kaing Khek Iev, better known as Duch, the director of the Khmer Rouge torture centre in Phnom Penh.