Greek Prime Minister George Papandreou faces a cliff-hanger confidence vote on Friday after his plan for a referendum on an EU/IMF bailout - supposed to save both Greece and the euro zone from disaster - backfired spectacularly.

Even if his socialist government survives the late-evening parliamentary vote, Papandreou's days as premier looked numbered amid opposition calls for his resignation and a deal with his cabinet under which, government sources said, he agreed to quit after negotiating a coalition with his conservative rivals.

Much of Greece and many European leaders reacted with horror after Papandreou abruptly announced Monday that he would put the 130-billion-euro ($180 billion) rescue plan, agreed at a euro zone summit only last week, to the Greek people.

After a tumultuous day in Greek politics, the chances of the referendum being held dwindled to almost nothing Thursday. Papandreou offered to drop the idea anyway if the conservative opposition backed the bailout in parliament.

But he came out fighting, rejecting opposition demands, in public at least, that he make way for a caretaker administration with just two tasks: forcing the bailout through parliament without a referendum and calling a snap election.

However, analysts said Papandreou may not be around much longer to fight such battles.

"The prime minister's position is very difficult, since he chose not to respond to the opposition's proposal for a transitional coalition government. Therefore I believe that it is unlikely that he will win the vote," said Costas Panagopoulos, head of ALCO pollsters.

Through waves of austerity policies demanded by Greece's international lenders, Papandreou has carried the parliamentary group of his PASOK party with him, despite much grumbling within the ranks.

But a steady trickle of defections has reduced his majority to the point that one or two waverers could inflict a defeat in the confidence vote, expected as late as midnight (6pm EDT).-Reuters