ISTANBUL: Turkish politicians made their last campaign rounds Saturday on the eve of an election that is expected to see Prime Minister Tayyip Erdogan win a third term and could give him a mandate to rewrite the constitution. Often cited as a Muslim nation with a working democracy, Turkey has become regarded as model for people in North Africa and Middle East living through the “Arab Spring”. Polling stations were due to open at 7.00 a.m. (0400 GMT) on Sunday in the east, and an hour later in the west. Turnout was expected to be high as is typical in Turkey and irregularities or violence were not expected to be concerns on polling day. The sale of alcohol was prohibited from 6.00 a.m. on Sunday. Opinion polls have shown Erdogan set to win four more years of single party rule, thanks in large part to his success in ending a cycle of crises to make Turkey one of the world's fastest growing economies. The only doubt was over the margin of victory. Erdogan needs more than a simple majority to be certain of pushing plans for a new constitution to replace one written in 1982, two years after a military coup. Turkey suffered three coups since 1960 and a fourth government was forced to resign by generals unhappy with a coalition led by an Islamist prime minister.