Turkey's parliament on 9 January begins debating a controversial new draft constitution aimed at expanding the powers of the presidency under Recep Tayyip Erdogan that is expected to be put to a referendum by the spring.
The new constitution, which would replace the basic law drawn up after Turkey's 1980 military coup, seeks to set up for the first time a presidential system for ruling the modern republic created from the ashes of the Ottoman Empire.
Critics have claimed that the move is part of a power grab by Erdogan, premier from 2003-2014 and then president, for one-man rule in the wake of the failed putsch in July.
But Erdogan and the ruling Justice and Development Party (AKP) say the system would bring Turkey into line with countries such as France and the United States and is needed for efficient government.
The debates on the 18-article new constitution will begin in the parliament chamber after the draft was agreed by a parliamentary commission ahead of the New Year. The two readings are expected to last 13-15 days.
The AKP needs more than 330 votes -- a three fifths majority -- for the bill to be submitted to a referendum for public approval.
However, the November 2015 election left the AKP short of a super majority in parliament and it is relying on the support of the opposition right-wing Nationalist Movement Party (MHP), the fourth largest party.
Once approved by parliament, a referendum should take place within 60 days, indicating a date in late March or early April.
Pro-government newspapers have predicted a thumping victory for the ruling party although other commentators have been more cautious.
The new constitution is opposed by the biggest opposition party the Republican People's Party (CHP) whose deputy chairman Bulent Tezcan said it would restore powers "to the palace" taken away from the Ottoman Sultan a century ago.
"It will be the dissolution of all that our republic has achieved," he said, criticising the draft as paving the way for "one man dictatorship".
But AKP lawmaker Halil Firat, who helped draw up the proposed new constitution, said it would make clear the roles of government and president.
"Stability will be achieved. Decision-making will be quick."
Under the new constitution, the president would not have to sever links with a political party, as is the case now even though Erdogan co-founded the AKP.
It is also expected to lead to the creation of the posts of vice presidents and the abolition of the office of prime minister.
There will no longer be a formal cabinet but there will be ministers. The president will have the power to appoint and fire ministers.
The draft law says the president would be elected for a five-year term and serve for a maximum of two mandates.