The lawyer for five Bulgarian nurses sentenced to death in Libya for infecting hundreds of children with HIV has appealed against their convictions.
Libya has faced strong criticism over the conduct of the trials
Othman Bizanti said he had lodged papers on their behalf on Saturday at the court where they had been tried in the capital, Tripoli.
The lawyer for a Palestinian doctor also convicted of infecting the children lodged an appeal last week.
Mr Bizanti said the Supreme Court should rule on the case by mid May.
The appeal to the Supreme Court is the last chance for the defence to have the guilty verdicts overturned.
The last say on the execution will be by Libya's Supreme Judicial Council, which could overturn any ruling by the Supreme Court.
The medics have been in detention since 1999, during which time 52 of the 426 infected children have died of Aids.
They have been sentenced to death twice by a Libyan court, once in May 2004 and again in December 2006.
Academic bodies have argued that the guilty verdicts run counter to scientific evidence.
The medics have protested their innocence throughout, retracting confessions that they said were obtained under torture and arguing that they are being made scapegoats for unhygienic hospitals.
The six foreign medics were arrested in 1999
Lawyers for the medics have argued that the HIV virus was present in the hospital, in the town of Benghazi, before the nurses began working there in 1998.
Medical experts including the French co-discoverer of the HIV virus had testified on their behalf.
Oxford University in the UK said the verdict ran counter to findings by scientists from its Zoology Department.
A research team had concluded that "the subtype of HIV involved began infecting patients long before March 1998, the date the prosecution claims the crime began", a statement from the university said.
Libya has asked for 10m euros (£6.7m) compensation to be paid to each of the families of victims, suggesting the death sentences could be commuted in return.
But Bulgaria has rejected the proposal, saying any payment would be seen as an admission of guilt.