By Guy De Launey
BBC News, Phnom Penh
Judges for the long-awaited Khmer Rouge trials have begun an important meeting in Cambodia's capital, Phnom Penh.
The judges have struggled to resolve their differences
Local and international legal officials are hoping to agree on the ground rules for the special courts.
The process has been delayed for more than six months because of disagreements among the judges.
As many as two million people are thought to have died during the four years of Khmer Rouge government in the late 1970s.
A packed hotel conference room was the venue for the opening ceremony of the judge's plenary session.
Academics, human rights workers and veteran observers of the trials all squeezed in for the occasion.
They were keenly aware that the next week of discussion could make or break the special courts.
The problem is simple to explain but rather more difficult to solve.
The courts are under Cambodian jurisdiction, but the UN-appointed legal officials have insisted that international standards of justice should apply.
The legacy of the Khmer Rouge years hangs over Cambodia
Allying those concerns while respecting local laws has been at the heart of the disagreements.
There have been months of behind-the-scenes negotiations since the previous plenary session ended in disarray last November.
Now the international judges, led by Dame Silvia Cartwright, say it is vital to move forward.
"The process of drafting and discussing the internal rules of procedure has taken too long," she said.
"We are hopeful that after the next week of work the final details of the rules will be put in place, and that the first stages of the trial process can begin."
If an agreement is reached, then the prosecutors will pass on their files to the investigating judges.
But some of the international officials have indicated they will quit if negotiations break down, and that could mean the end of the process.