Turkey is heading toward a historic referendum on a new political system that could change the course of its history — and it has the country divided right down the middle.

For supporters, change will bring much-needed stability. Others fear it could lead Turkey down the path of an autocratic, one-man rule by President Recep Tayyip Erdogan.

Voters will decide on Sunday whether to approve constitutional changes that would replace the parliamentary system with a presidential one, scrapping the office of the prime minister and handing over its powers to the president.

Erdogan, who has fronted the campaign for a "yes" vote, says the proposed "Turkish style" presidential system will banish weak governments, establish an efficient state and bring prosperity to the country.

A "yes" vote would allow a set of 18 constitutional reforms that grants the president the power to appoint government ministers and senior officials, appoint half of the members in the country's highest judicial body, declare states of emergency and issue decrees.

Critics argue that will allow Erdogan — who has been in power either as prime minister or president since 2003 — to rule at least until 2029 with few checks and balances in a system where the separation of powers will be less clear-cut.

"The 18 articles foresee a very loose separation of powers," said Ahmet Kasim Han, an associate professor of international relations at Kadir Has University in Istanbul. That "unduly invests the weight of the decisions and the power of the executive on the president," he said.

Polls suggest a neck-and-neck race for Sunday's vote.

"It's going to be a very close call and both 'yes' and 'no' are equally probable as outcomes," Han said.

The referendum comes amid troubled times for Turkey, which has been plagued by a string of bombings, renewed violence between the government forces and Kurdish rebels and a failed coup attempt in July that resulted in a state of emergency that remains in place.

The emergency powers have permitted a widespread government crackdown that has targeted the followers of U.S.-based Muslim cleric Fethullah Gulen — whom Turkey blames for the coup — and other government opponents. Some 100,000 people — including judges and teachers — have been dismissed, and more than 40,000 people, including journalists and opposition pro-Kurdish legislators, have been arrested. Hundreds of news outlets and non-governmental organizations have been shut down.

The country is also dealing with the war in neighboring Syria which led to an influx of some 3 million refugees. Turkey has sent troops into Syria to help opposition Syrian forces clear a border area from the threat posed by Islamic State militants.

Meanwhile, Turkey is drifting further apart from Europe, following Erdogan's recent outbursts slamming the governments in the Netherlands and Germany as "Nazis" over their restrictions on Turkish ministers' attempts to court Turkish expatriate votes.

For Erdogan, 63, a presidential system has been a long-time dream.

A prime minister for 11 years since 2003, he was elected president in 2014 for a five-year term and took a far more active role in politics than his predecessors, ruling behind the scenes despite the current constitution that requires him to be neutral.

Erdogan argues that as Turkey's first president to be directly elected by the people — instead of the parliament — he has a wider mandate than previous presidents.

If approved, the reforms would in effect legalize his de facto rule.

The amendments were approved by parliament in January, but fell short of the majority required to directly come into effect without a national vote.

Erdogan remains popular in Turkey's conservative and religious heartlands, where he is seen as a strong leader who stands up against Europe, terror threats and coup-plotters. Many believe he has improved services and health care, and given a voice to pious Muslims who at times felt marginalized by more secular governments.

He has crisscrossed the country to hold mass rallies and led an often abrasive and divisive campaign, accusing his opponents of siding with "terrorists."

In rally after rally, he has argued that the new system will end periods of unstable governments and coalitions, prevent coups similar to last summer's failed attempt, and stop the system of dual leadership between the prime and the president.

"If only we could have instituted these changes years ago," he said during a campaign speech this week. "We have paid dearly for these delays."

The opposition has complained about an unfair campaign process, with Erdogan and the "yes" propaganda dominating air waves and billboards using state resources. The main opposition party has recorded more than 100 incidents of obstruction to their campaign efforts, including threats, beatings and arbitrary detentions.

The Organization for Security and Cooperation in Europe, which will be observing the referendum, noted in a report last week that the vote is taking place under the state of emergency under which "fundamental freedoms have been curtailed and thousands of citizens have been detained or dismissed, including civil servants, judges, journalists and opposition party members."

It also noted that supporters of the "no" campaign have faced "bans, police interventions, and violent scuffles at their events."

If approved in the referendum, the reforms would come into effect with the next general elections slated for 2019.


Associated Press journalist Bram Janssen in Istanbul contributed.