The Iraqi government and Arab countries have broken into bitter squabbling ahead of a Baghdad conference on Saturday that the United States had hoped would finally unite them in efforts to stabilize the war-torn nation. Sunni-led Arab governments plan to use the conference to press for a greater Sunni role in Iraq. That has rankled Iraq's Shi'ite leaders, who believe the Arabs are trying to reverse their new-found power after decades of being marginalized under Sunni minority rule. The dispute reflects the complicated tensions that are likely to surface at the Baghdad meeting, which gathers diplomats from Iraq's Arab neighbors, Iran, the United States, Turkey and the permanent members of the UN Security Council. Arab states are likely to try to rally the United States behind their demands, increasing the pressure on Baghdad. Iran has vowed to support its Shi'ite allies in the Iraqi government - but is also concerned the US will press it on accusations that Teheran is supporting Shi'ite militants fueling Iraq's bloodshed. The United States has struggled to rally its Arab allies behind the Shi'ite-led government since the 2003 fall of Saddam Hussein and hopes the Saturday meeting will be a chance to show Arab support for Baghdad. But Egypt, Saudi Arabia and Jordan - who opposed the US-led invasion that toppled Saddam - have remained deeply suspicious of the Shi'ites, accusing them of sidelining Iraq's Sunni minority and being proxies for extending Iran's power in the Middle East. Earlier this week, the Cairo-based Arab League said its delegation to the conference would press for changes in Iraq's constitution and government to give Sunnis more political power. Arab nations argue such a step is necessary to ease the Sunni-led insurgency that has bloodied Iraq for three years. Arab League Secretary-General Amr Moussa suggested that Arab governments would take their proposals to the UN Security Council, a move that would be seen as challenging the legitimacy of Iraq's government, led by Shi'ite Prime Minister Nouri al-Maliki. The Shi'ite coalition that dominates al-Maliki's government on Thursday angrily denounced Moussa's comments, saying they were a "flagrant interference in Iraq's internal affairs" and "ignored the march of the Iraqi people to build a free and democratic state." "While we regret these irresponsible positions which incite discord and acts of violence inside Iraq, we hope they will not cast their shadow on the conference," the Shi'ite United Iraqi Alliance said in a statement. Iraq's Shi'ite deputy parliament speaker, Khalid al-Atiyah, said Moussa's comments "might encourage some parties to take some Arab countries to their sides to accomplish their political desires" - referring to Iraqi Sunnis. The Shi'ites and Kurds who dominate Iraq's government have long accused Arab states of failing to support them because of bitterness over the Sunnis' fall from power. Under Saddam, the Sunni minority ran the country, and the other two communities were brutally suppressed. Shi'ite anxiety has deepened as the United States - the Iraqi government's top ally - has begun working more closely with its Arab allies to resolve a series of Mideast crises, including Lebanon, the Israeli-Palestinian conflict and Iran's controversial nuclear program. Shi'ite leaders fear Sunni Arab governments are maneuvering to back former Iraqi prime minister Ayad Allawi to form a new coalition with greater Sunni support - and they fear the Arabs are seeking to sow divisions within al-Maliki's coalition. On Wednesday, a key Shi'ite party, the Fadhila Party, withdrew from the pro-al-Maliki United Iraqi Alliance citing "faulty sectarian policies." Arab nations, in turn, have expressed concern over rising Iranian influence among Iraqi Shi'ites - part of what they and the United States fear is Teheran's growing power in the Mideast. On Wednesday, the former Saudi ambassador to Washington prince Turki al-Faisal warned that an Iran-backed Shi'ite axis would lead to "the collapse of peaceful coexistence across the spectrum of the Arab society with all its sects and creeds." Iran comes into the gathering vowing to back its Shi'ite allies. Iranian Foreign Minister Manouchehr Mottaki said the meeting should "result in sending a clear message that the countries of the region are standing alongside the government and nation of Iraq. The gathering could provide a crucial opportunity for talks between the United States and Iran, though it is not clear if they will hold direct meetings on the sidelines of the multilateral conference. It is the first time in more than two years that Washington appears ready to meet with Iran over Iraqi security. US Secretary of State Condoleezza Rice and her Iranian counterpart attended a multilateral gathering in September at the United Nations in September, but that dealt with Iraqi economic goals and the two did not hold bilateral talks. The United States will be represented at the session by Rice's senior adviser on Iraq, David Satterfield, and the outgoing US ambassador to Iraq, Zalmay Khalilzad. Iran's delegation will be led by Deputy Foreign Minister Abbas Araghchi.