By Daren Butler
ISTANBUL (Reuters) - Tayyip Erdogan was poised to become his country's first elected president as Turks go to the polls on Sunday, fulfilling his dream of what he calls a "new Turkey" and what his opponents say will be an increasingly authoritarian and polarized nation.
A victory for Erdogan would seal his place in history after more than a decade as prime minister in which Turkey has emerged as a regional economic power, riding on a wave of religiously conservative support to transform the secular republic founded by Mustafa Kemal Ataturk in 1923.
But his critics warn that a President Erdogan, with his roots in political Islam and intolerance of dissent, would lead the NATO member and European Union candidate further away from Ataturk's secular ideals.
"God willing a new Turkey will be established ... a strong Turkey is rising again from the ashes," Erdogan said on Saturday in his final campaign speech in the conservative stronghold of Konya in central Turkey.
"Let's leave the old Turkey behind. The politics of polarization, divisiveness and fear has passed its expiry date," he told an enthusiastic crowd of thousands who waved Turkish and Erdogan campaign flags and chanted his name.
Opinion polls put Erdogan, 60, far ahead of his two rivals who are competing for a five-year term as president. Parliament has in the past chosen the head of state but this was changed under a law pushed through by Erdogan's government.
He has set his sights on serving two presidential terms, keeping him in power past 2023, the 100th anniversary of the secular republic. For a leader who refers frequently to Ottoman history in his speeches, the date has special significance.
The prime minister has vowed to exercise the full powers granted to him by current laws, unlike his predecessors who have played a mainly ceremonial role. But he also plans to change the constitution to establish a fully executive presidency.
The constitution, written under military rule following a 1980 coup, enables him to chair cabinet meetings and appoint the prime minister and members of top judicial bodies, including the constitutional court and supreme council of judges.
Opinion polls have put Erdogan's support at 55-56 percent, giving him the majority he needs to win on Sunday. If there is no outright winner, a second round will be held on Aug. 24.
Surveys put him some 20 points ahead of the main opposition candidate, Ekmeleddin Ihsanoglu. Selahattin Demirtas, head of the pro-Kurdish left-wing People's Democratic Party, is seen winning just short of 10 percent of the vote.
Turks living abroad have been able to vote at the country's airports for the last two weeks. One man voting at Istanbul's main Ataturk Airport on Saturday voiced his concerns about what he said was "one-man rule getting stronger every day".
"I don't see a place for myself in that new Turkey Erdogan keeps talking about, that's why I stay living abroad," said Umit, 33, who lives in Dubai.
"A lot of the things that happen here do not happen in democratic countries. I live in an Islamic country, yet I feel more free."
Erdogan's ruling AK Party won a clear victory in local elections in March and a victory on Sunday would emphatically put an end to the toughest year of his time in power.
He was shaken by nationwide anti-government protests last summer, and months later, Erdogan and his inner circle were targeted by a corruption investigation and a power struggle with his former ally, U.S.-based cleric Fethullah Gulen.
He accuses Gulen of seeking to overthrow him and has vowed as president to continue purging institutions such as the police and judiciary where Gulen is believed to wield influence.
Another voter at Ataturk Airport was more focused on the strong economic growth and development which Turkey has experienced since his party came to power in 2002 - one of the primary reasons for Erdogan's electoral success.
"Every year I come to Turkey for holidays and I can observe the immense change it has undergone. Roads, bridges, the services carried out in state institutions," said Halis, 46, who lives in Cologne with his wife, who wears a headscarf.
"How could they call someone who has done so much good for his country a dictator?"
(Additional reporting by Humeyra Pamuk; Writing by Daren Butler; Editing by Sophie Hares)