Tripoli - Libya's UN-backed prime minister Fayez al-Sarraj called on Monday for a referendum on a draft constitution approved over the weekend following years of wrangling in the war-torn country.Libya had no constitution throughout the four-decade dictatorship of Moammar Gaddafi, who was overthrown and killed in a NATO-backed 2011 uprising.Libyans elected a 60-member panel in 2014 to draft one, although the vote was marred by low turnout as public frustration mounted over the weak central government's failure to restore order in the wake of the uprising.The panel finally voted through its draft constitution on Saturday, paving the way for a national referendum to enshrine it into law.The document defines the structure of power, the status of minorities, the role of Islamic law in legislation and seeks to create institutions capable of restoring stability after years of violence.The vote in the eastern city of Baida was disrupted by protesters, but the draft finally passed by 43 votes out of the 44 members present.Sarraj on Monday "welcomed the vote by the Constituent Assembly on the draft Libyan Constitution", according to a statement on the unity government's Facebook page."Freedom of opinion and expression must be respected by all, along with the right of all the Libyans to choose their way of life without terror or threat," he said.He called on political actors to "create a suitable climate" for holding a referendum on the constitution.If passed, the draft text would make Libya a republic with a president and two houses of parliament. Tripoli would remain the capital, Islam would be the state religion and Islamic law a source of legislation. Arabic would be the language of the state, but the text also recognises the languages of Libya's Berber, Toubou and Tuareg minorities.The Assembly had 18 months to write the draft but was bogged down by political unrest.Sarraj's Government of National Unity, the result of UN-backed talks, has struggled to impose its authority across the country and is not recognised by a rival government in Libya's east.But last week Sarraj met Khalifa Haftar, a powerful eastern-based military commander who backs the rival administration, for French-backed talks aimed at resolving the main split in the country. The two called for a ceasefire, peace talks, elections and "building the rule of law" in a country where dozens of armed groups have thrived in the power vacuum created by Gaddafi's ouster.