The Palestinians have won backing to lead the biggest bloc of developing countries at the United Nations, raising their profile at the world body despite opposition from the United States. <br />''<br />''The General Assembly yesterday voted overwhelmingly to grant the observer-state of Palestine temporary rights to act as chair of the Group of 77 plus China, a bloc that has grown to 134 countries at the United Nations.  <br />''<br />''A resolution drafted by Egypt was adopted by a vote of 146 to 3 with 15 abstentions. The United States, Israel and Australia were the only three countries to oppose the measure in the 193-nation assembly.<br />''<span style="color: #222222;"><br />'' US Ambassador Nikki Haley branded the decision a UN mistake, recalling that the Palestinians are not a UN member state or any state at all and should not be granted privileges reserved for full-fledged members.</span><br />