French President Francois Hollande said his country was doing "everything" it can to save Serge Atlaoui from the firing squad after his appeal against the death sentence was rejected on Monday by the courts in Indonesia.
The State Administrative Court in Jakarta dismissed Atlaoui's appeal, upholding its previous decision in April that it did not have the jurisdiction to hear the challenge to the clemency plea.
"It will be up to the lawyers to decide what other avenues to pursue," Hollande told reporters after a European summit in Brussels on Monday. "France, without going into the legal debate, is doing everything to keep Serge Atlaoui alive."
According to AFP, Indonesian authorities had indicated that the execution will not take place during the fasting month of Ramadan, which ends mid-July.
Atlaoui, a welder was arrested in 2005 in a secret drugs factory outside Jakarta, with authorities accusing him of being a chemist at the site. The father of four however has maintained his innocence, claiming that he was installing machinery in what he thought was an acrylics plant.
He was initially sentenced to life in prison but the Supreme Court amended the sentence to death on appeal.
AFP said France has mounted a diplomatic campaign to save him, warning Jakarta of unspecified consequences if he is put to death and questioning Indonesia's legal system.
Following the latest court decision, France's European Affairs Minister Harlem Desir said: "The whole of the French diplomatic service" was being mobilised to save Atlaoui."
Atlaoui was to have been executed together with eight other drug offenders two months ago but won a temporary reprieve following pressure from Paris with Indonesia agreeing to allow an outstanding appeal run its course.