Rabbi Ovadia Yosef, 92, the spiritual leader of Israel\'s ultra-Orthodox Shas party, was taken to hospital early on Saturday after suffering a mild stroke, a colleague said. \"There was a stroke. It was small; it didn\'t cause much damage,\" Aryeh Deri, a leading member of Shas and long-time Yosef confidant, told an Israeli TV station. \"His speech is fluent. He is fully aware and able to concentrate,\" said Deri, who visited his mentor in hospital during the day. \"God willing he will be discharged soon.\" The all-powerful Yosef, who heads the Council of Torah Sages, Shas\'s supreme body, was taken to Jerusalem\'s Hadassah Ein-Kerem hospital for a series of tests after feeling unwell, Deri said. The influence of the former Chief Rabbi of Israel is not limited to the world of Sephardic Jewry. Political leaders are always keen to secure his backing because of the pivotal role the Shas party can play in forming any coalition government: to ignore Shas is to alienate around half a million voters. Shas currently has 11 members in the 120-seat Knesset, or parliament. The latest opinion polls predict that it will win 10-12 seats in the early general election called for January 22. Last August, Prime Minister Benjamin Netanyahu was reported to have sent one of his closest aides to win Rabbi Yosef\'s backing for any Israeli military attack on Iran. Israel -- the Middle East\'s sole if unacknowledged state to have the atomic bomb -- and Western powers suspect the Islamic republic of carrying out a covert nuclear weapons programme, a charge Tehran vehemently denies.