* Russia warns resolution could hinder Syria conference
* U.N. assembly voted 133 in favor of August resolution
* Western diplomats predict less support on Wednesday
By Michelle Nichols
UNITED NATIONS, May 15 (Reuters) - The U.N. General Assembly is set to vote on Wednesday on a draft resolution that condemns Syrian authorities and accepts the opposition Syrian National Coalition as party to a potential political transition.
Russia, a close ally of Syrian President Bashar al-Assad, is opposed to the resolution, which was drafted by Qatar and other Arab nations and circulated among the 193 U.N. member states. Some Western diplomats said it was unlikely to win as many votes as a resolution that passed last year with 133 in favor.
No country has a veto in the General Assembly.
"I'm convinced a lot of countries voted for this text because they believed they were voting for the winning side," a senior western U.N. diplomat, speaking on condition of anonymity, said in reference to the August, 2012 resolution. "They are not so sure anymore."
"Now also you have the Islamist, terrorist factor which is much more conspicuous," he said.
The Syrian conflict started more than two years ago with mainly peaceful demonstrations against Assad, but turned into a civil war in which the United Nations says at least 70,000 people have been killed. Islamist militants have emerged as the most potent of the anti-Assad rebels.
Wednesday's vote comes as Washington and European governments have been mulling the benefits and risks of supplying arms to Syrian rebels.
Another senior U.N. diplomat, who also spoke on condition of anonymity, said this draft resolution was stronger than the earlier resolution, prompting Russia to write to all states to complain that it was unbalanced. The diplomat said Russia had also warned that it could hinder preparations for a Syria peace conference, as agreed by Russia and the United States.
A dispute between Russia and the United States over how to end Syria's war has left the U.N. Security Council paralyzed to act. They both agreed last week to convene a peace conference on Syria, but that plan already appears to be hitting snags over who should represent the opposition.
The current draft U.N. resolution welcomes the establishment of the Syrian National Coalition "as effective representative interlocutors needed for a political transition."
CHEMICAL WEAPONS PROBE
But diplomats said some countries may be concerned that the draft resolution could be considered as official U.N. recognition of the coalition as the representative of the Syrian people.
"It's very likely the vote will not be as high as last year," said another senior western U.N. diplomat, speaking on condition of anonymity. "But we clearly don't want the numbers to go below 100 or 110."
The Syrian National Coalition has been recognized by the 130 international representatives comprising the "Friends of Syria" group of nations and the Arab League as "the legitimate representative of the Syrian people."
The draft resolution condemns "all violence, irrespective of where it comes from," continued escalation in the use of heavy weapons by Syrian authorities, the shelling and shooting by Syrian troops into neighboring nations and human rights abuses.
It also demands that the Syrian authorities grant unfettered access to a U.N. team investigating allegations that chemical weapons have been used in the conflict. The Syrian government and the opposition have accused each other of carrying out chemical weapons attacks. Both deny the accusations.
The draft resolution further welcomes Arab League decisions relevant to reaching a political solution, but does not reference an agreement by the league that member states have the right to provide military support to Syrians fighting Assad's troops.
In August there were 12 votes against the Syria resolution and 31 abstentions and some countries did not participate. Russia was among those that opposed it. China, Iran, North Korea, Belarus, Cuba and other states that often criticize the West also voted against it.
The draft resolution reaffirms U.N. support for U.N.-Arab League Syria mediator Lakhdar Brahimi, who recently agreed to stay on in the role despite his frustration at the international deadlock that has prevented Security Council action to halt the conflict. (Reporting by Michelle Nichols; Editing by Paul Simao)
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