Tunisia's Islamists resist proposal to step down TUNIS (Reuters) - Tunisia's ruling Islamists rejected on Monday a proposal under which they would step down pending elections, a decision likely to deepen confrontation with secular opponents demanding their immediate resignation. Tunisia, whose 2011 uprising was the first of a series across the Arab world, has been in turmoil since an opposition leader was assassinated in July, threatening a democratic transition once seen as the most promising in a troubled region. The country's powerful UGTT union had been pushing both sides to accept a plan for the Islamist-led government to step down after three weeks of talks to decide on a date for elections and the composition of a new caretaker administration. But the moderate Islamist Ennahda party called on Monday for more guarantees on the election date and said an assembly writing a new constitution should finish its work before the government agreed to relinquish power. "We have said that this government would not step down concretely before the completion of the constitution," Rafik Abd Essalem, a senior Ennahda official, told reporters. Frustrated at lack of progress, the 800,000-member UGTT labor union on Sunday threatened to mobilize protests to pressure the government to accept the proposal that it should step down to make way for a transition cabinet. "We cannot accept the threat of pressure from the streets," said Ennahda vice president Adb el Hamid Jelassi. There should be more guarantees. Since autocrat Zine al-Abidine Ben Ali fell in 2011, Tunisia has faced growing divisions over the political role of Islam, with the opposition accusing Ennahda of promoting an Islamist agenda in one of the Arab world's most secular nations. After suspected Islamist militants shot dead an opposition leader in July, the second such assassination this year, Ennahda came under mounting pressure and street protests from an opposition emboldened by events in Egypt, where the military overthrew a freely elected Islamist president the same month. Ennahda had initially accepted that it would step down under the proposal but has resisted pressure it resign immediately and has expressed reservations that it said would need to be discussed during the planned negotiations. A National Assembly writing the country's constitution had almost completed its work before it was suspended a month ago over the political crisis. Deputies got back to work last week though most opposition members stayed away. Unlike Egypt and Libya, Tunisia's transition to democracy has been mostly peaceful, and its military has no tradition of political interference. Ennahda has also governed with two smaller secular partners. But prolonged political wrangling is already worrying Tunisia's international lenders who want to see progress to full transition and reforms to fuel subsidies to help ease the country's fiscal deficit. Reporting by Tarek Amara; writing by Patrick Markey; Editing by Ralph Boulton