Bulgaria insists the medical workers are innocent and used as scapegoats by Libya.
The six health workers have said they are innocent and were tortured into making a confession.
Some scientists have said negligence and poor hygiene were the real culprits and that the infections started before the six arrived at the hospital.
Relatives of the children have said the infections were part of a Western attempt to undermine Muslims and Libya.
Governments of the EU have been hopeful the six will be set free after successful negotiations with an association of families to reach a financial settlement.
Both sides have suggested agreement is close and Libya has hinted it could free the nurses if an accord is reached.
The families have asked for compensation of $13.3 million for each infected child’s family – “blood money” under which Islamic law lets victims’ relatives withdraw death sentences in return for reparations.
Bulgaria and the EU refuse to accept the idea of compensation, which would imply the six were guilty, but the EU has offered a fund to pay for the children’s future care.
Libyan officials have said the council could take several sessions to reach a final decision and will only agree to the release of the nurses if a settlement has been reached in the private talks between the families and the EU.
Mohammed Abdel-Rahman Shalgam, the Libyan foreign minister, said: “The council will take into consideration several factors like compensation, the age, and the time spent by the prisoners in jail.”