UNITED NATIONS (Reuters) - The United Nations Security Council is due to vote on Thursday on rival U.S. and Russian bids to renew an international inquiry into chemical weapons attacks in Syria, diplomats said, a move that could trigger Russia’s 10th veto to block action on Syria.

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The mandate for the joint inquiry by the U.N. and the Organization for the Prohibition of Chemical Weapons (OPCW), which found the Syrian government used the banned nerve agent sarin in an April 4 attack, expires at midnight Thursday.

The United States was first to ask for a vote on its draft resolution, followed quickly by Russia. A resolution needs nine votes in favor and no vetoes by the United States, France, Russia, Britain or China to be adopted.

Diplomats say there is little support among the 15-member council for the Russian draft, which Russian U.N. Ambassador Vassily Nebenzia has said aims to correct “systemic errors” of the inquiry, known as the Joint Investigative Mechanism (JIM).

Russia has vetoed nine resolutions on Syria since the conflict started in 2011, including blocking an initial U.S. bid on Oct. 24 to renew the JIM, saying it wanted to wait for the release two days later of the inquiry’s report that blamed a sarin gas attack on the Syrian government.

“The United States hopes the Security Council will stand united in the face of chemical weapons use against civilians and extend the work of this critical group,” the U.S. mission to the United Nations said in a statement on Wednesday.

“Not doing so would only give consent to such atrocities while tragically failing the Syrian people who have suffered from these despicable acts,” it said.

While Russia agreed to the 2015 creation of the inquiry, known as the Joint Investigative Mechanism (JIM), it has consistently questioned its findings, which also concluded that the Syrian government used chlorine as a weapon several times.

A spokesman for the U.S. mission to the United Nations said on Monday that Russia has refused to engage in negotiations on the U.S. draft resolution. Diplomats said the United States had amended its draft in a bid to win Russian support.

British U.N. Ambassador Matthew Rycroft warned on Wednesday that if the inquiry ended: “The only victors would be people who want to use chemical weapons in Syria, which is the (Syrian President Bashar) al-Assad regime plus Daesh (Islamic State).”

“Everyone in the Security Council would be shooting ourselves in the foot if we allowed that to happen,” he said.

The Russian mission to the United Nations was not immediately available for comment on the impending council vote.

If the inquiry is not renewed, Nebenzia said on Monday: “It may send a bad signal, but the way the investigation has been conducted sends an even worse signal.”

Syria agreed to destroy its chemical weapons in 2013 under a deal brokered by Russia and the United States.