The trial is expected to last two or three days and will take place "before the end of December," a senior justice official said.
Members of Zoe's Ark have claimed that their case is being ignored and say they have been abandoned by the French government.
"They are a bit strained. They had been preparing for the worst and now it appears this was justified," Lamia said.
Zoe's Ark has claimed that it wanted to foster children from Sudan's war-torn Darfur region to families in Europe, but UN officials who questioned the children said that the vast majority were not orphans.
|Zoe's Ark said the children were orphans |
from Sudan's Darfur region [AFP]
Legal experts in Chad have in recent weeks been debating whether the French aid workers should face criminal or civil charges after being arrested for planning to fly the children out of the central African country.
"We're bit surprised at how things have happened, because the facts of the case did not necessarily mean ... it would be a criminal trial," Lamia said.
He also suggested there had been political meddling in the case.
"We've seen that politics has tried to eclipse the judicial process and we regret that."
The suspects also face charges of lying on official documents and non-payment of rent. 'Common will'
Nicolas Sarkozy, the French president and Idriss Deby, his Chadian counterpart discussed the case on the sidelines of an EU-Africa summit in Portugal on Saturday.
They had a "common will to resolve the situation", a French presidential spokesman said.
Deby has publicly vowed to punish those responsible for what he termed a "horrible act" and a "crime".
France has strongly condemned the Zoe's Ark operation but the case has strained relations with its former colony ahead of the deployment of a European Union peacekeeping force in the east, in the coming weeks.