The deterioration in the health of 93-year-old Rabbi Ovadia Yosef has thrown his party, Shas, into a battle over who will succeed the spiritual leader.

Hospitalised at Hadassah Medical Centre for more than two weeks because of a blood pressure problem, doctors had to put the rabbi into a coma after his kidney and heart showed signs of failing. Last weekend there was some improvement, but his situation remains critical.

For the past three decades, Rabbi Yosef has led Shas with an iron hand, controlling its parliamentary list and instructing MKs on how to vote.

Four rabbis are being mentioned as possible successors. Shalom Cohen is the most senior member of the Council of Torah Sages, which nominally controls the party, but he is 82 and is seen as lacking in political sophistication.

Rabbi Ovadia’s son, Yitzhak, is seen as a successor but his recent election as the new chief rabbi means he cannot be overtly involved in politics.

Former Chief Rabbi Shlomo Amar was once seen as the anointed successor but he has become estranged from the Yosef family in recent months. Rabbi Reuven Elbaz has a support base but was involved in corruption allegations