In Turkey, a referendum is being held on amendments to the country's constitution. The constitution was written in 1982 by Turkey's then military rulers and the government claims the vote offers a chance to sever its ties with military rule. But opponents claim its a power grab by the government through the judiciary.

49 million Turks have registered to vote in what analysts say is one of the most bitterly contested votes in recent Turkish history.

Prime Minister Recep Tayyip Erdogan has campaigned tirelessly across the country for what he says is an historic vote for democratizing Turkey.

The 26 amendments include putting the military under the jurisdiction of civilian courts. Women and trade unions are also given greater rights.

Such reforms are largely uncontroversial and there is a political consensus on replacing the 1982 constitution which was written by Turkey's then military rulers.

But there is deep division over the government's proposed changes to the judiciary. These include giving parliament greater powers in appointing constitutional court judges and prosecutors.

Leaders of the main opposition parties say the government with its large parliamentary majority and a former member as President its seeking to remove one of the last checks to its power.

In Taksim square, one the main shopping districts for Istanbul residents, people on the street seem deeply divided over how to vote.

I will vote yes , this man says, because he says we don't have a democratic constitution. Its coup constitution.

But a voter has concerns over the motive of the government.

"I don't trust the political party power, because the real reason is to control the state more, it is becoming a kind civilian authority rather for democracy we need more, and probably larger compromise between the different groups in Turkey," he said.

According to most opinion polls the Turkish people are split down the middle with the result being considered too close to call. Much of the opposition, according to analysts, centers on whether the ruling AK party with its Islamic roots , poses a threat to the 87 year old secular state.

The government denies it does. But political columnist Nuray Mert says the referendum reveals how deeply divided Turkey remains.

"Everyone believes that the margin will be very little and that will mean that Turkey is divided into half and the gap between the 2 camps is widening every day," said Mert.

The Turkish president Abdullah Gul called on Turks to vote and the turnout is predicted to be high. But with a close result expected analysts say there is little hope the referendum will heal the deep divide in Turkish society.