Turkey's constitutional referendum today Sunday April 16,2017

Turkey goes to the polls Sunday April 16,2017 in a controversial constitutional referendum, which if passed, would grant President Recep Tayyip Erdogan sweeping executive powers by replacing the parliamentary system with a presidential one.

Turkish President Recep Tayyip Erdogan casts his vote accompanied by his wife Emine Erdogan at a polling station in the Uskudar district of Istanbul

Voters were being asked to endorse an 18-article reform package put forward by the ruling Justice and Development Party that would replace the current system of parliamentary democracy with a powerful executive presidency

President Recep Tayyip Erdogan’s supporters say a strong president is needed to handle the country’s myriad challenges, including terror threats from jihadist and leftist groups, the fallout from the Syrian Civil War -- which has seen around 4 million refugees flee to Turkey -- and lowered economic growth.

Critics however argue that the new constitution will condemn Turkey to the elected dictatorship of Erdogan, an Islamist politician who has been in power since he was voted prime minister in 2003.

Over the past few weeks, giant posters for an “Evet” – or Yes – vote have dominated the skyline in major Turkish cities, while supporters of a “Hayir” – or No – vote complain of obstruction and intimidation from the opposite camp. The "no" campaigners say they have recorded more than 100 incidents of intimidation, beatings and arbitrary detentions.

If passed, the new measures would amount to the biggest constitutional upheaval for the country since its foundation in 1923 after the demise of the Ottoman Empire.

President Recep Tayyip Erdogan said he believed Turks would vote with "common sense", adding: "Hopefully once the polls are closed and votes are counted, Turkey will march towards the future by making the expected choice."

Evoking the revered founder of modern Turkey he said. "This referendum is no ordinary vote ... We are realizing the dream of Mustafa Kemal Ataturk to make Turkey a more civilized country."