JERUSALEM (AFP) - The health of former Israeli premier Ariel Sharon has worsened over the past hours, hospital officials said on Thursday, describing him as being in "extremely critical" condition.

"Over the past hours, there has been a worsening of the condition of former prime minister Ariel Sharon. His condition is described as extremely critical and his family is at his side all the time," said a statement from Sheba hospital near Tel Aviv where he is being treated.

Mr Sharon has been in a coma since January 4, 2006 after suffering a massive stroke, but his condition took a sudden turn for the worse on January 1 when he suffered serious kidney problems after surgery.

Hospital sources quoted by army radio said the former premier only had "a few days or even hours" left.

The long-time leader of the rightwing nationalist camp in Israeli politics, Mr Sharon suffered a massive stroke on January 4, 2006, slipping into a coma from which he has never recovered.

Following an extraordinary and controversial career stretching back more than half a century, Mr Sharon became convinced Israel needed to separate from the Palestinians and unilaterally determine its own borders.

While his government was initially seen as the most hawkish in Israeli history, less than four years after his 2001 election, Mr Sharon pulled out all troops and settlers from the Gaza Strip, which was occupied in the 1967 war.