The spiritual leader of the Shas party and leading Sephardic Torah scholar Rabbi Ovadia Yosef has been placed on a respirator after his condition deteriorated this evening.
The rabbi, who was admitted to Hadassa Ein Karem hospital late last week, remains fully conscious, according to doctors.
Earlier Monday, a statement from the hospital described Rabbi Yosef's condition as "stable," following a successful dialysis treatment.
However, soon after the rabbi's condition took a turn for the worse, after scans revealed fluid in his lungs, leading Shas officials to cancel Sukkot celebrations and call for mass prayers on his behalf.
The last few weeks have seen a deterioration in Rabbi Yosef's condition. Two months ago, the rabbi fell and broke a vertebra. Although he has since recovered, he is still troubled by pain following the fall. Rabbi Yosef was hospitalized several times since then to help improve his condition and relieve his pain.
On Sunday, Rabbi Yosef underwent an operation to implant a pacemaker for his heart, and the hospital said the operation had been carried out successfully.
Shas head MK Aryeh Deri issued a plea to "every individual - secular and religious - to unite at this time and pray for his health," adding that God "will not reject the prayers of the masses."
Those wishing to pray for his health are asked to pray for Ovadia ben Georgia.