Ayyash stands accused of coordinating the February 2005 bombings that killed former Lebanese prime minister Rafik Hariri and 22 others. He is still at large.
The defence counsel, Emile Aoun, acknowledges the controversial reputation of the Special Tribunal on Lebanon (STL).
"I know that the STL is a very divisive issue among many Lebanese, that’s clear," he told the Daily Star. "But to me it’s not so much about politics. This is simply about the rights of the accused and a fair trial in their absence."
Unless Ayyash is caught, he will be the first person tried in absentia by an international tribunal since the proceedings against Nazi suspects in Nuremberg in the 1940s.
The STL has been criticized for the narrowness of its mandate, which covers a limited number of attacks in 2004 and 2005, and for the burden it places on the annual Lebanese budget. It was created under the auspices of the UN, but will try crimes under Lebanese law.
Rafik Hariri's assassination led to a series of political crises, killings, and bombings that ignited sectarian clashes in 2008, leading Lebanon to the brink of civil war.
Aoun, the main defence lawyer, is a believer in international justice, but says it is "selective, expensive and slow." Asked when the process could conclude, Aoun quipped: "the two slowest forms of justice are God's justice and international justice".
Proceedings at the Special Tribunal on Lebanon will begin next January.
Read More about the Special Tribunal on Lebanon here. For a timeline of events around the 2005 bombing, follow this link. Story source here.
(Photo: The corner where Rafik Hariri was assassinated. http://www.flickr.com/photos/maccise/54199073/sizes/l/in/photostream/ )