Update 11.51pm: Italian prime minister Matteo Renzi has said he is resigning after a stinging defeat on a constitutional reforms referendum on which he staked his premiership.
"Good luck to us all," Mr Renzi told reporters after saying he would tell a Cabinet meeting on Monday of his decision, then tender his resignation to the Italian president, after more than two years in office.
— Alejandro Alvarez (@aletweetsnews) December 4, 2016
Mr Renzi conceded defeat after exit polls showed his proposal losing by a margin of about 60% to 40% in today's ballot.
Proposals contained in today's Italian referendum are set to be defeated, according to exit polls.
A Piepoli Institute exit poll for state TV channel RAI estimated that between 54-58% voted No, while 42-46% voted Yes.
Exit polls indicate 54/58% No, 46/42 Yes. Now we know why Renzi has called press conference. Italy.— Andrew Neil (@afneil) December 4, 2016
Two other polls gave 'No' a lead of around 10 points.
Exit polls indicate a clear loss for Renzi in Italian referendum, and big challenge for euro zone.— Tom Buerkle (@tombuerkle) December 4, 2016
Sky Italia exit poll has it for NO -- 57 to 43%— Andrew Neil (@afneil) December 4, 2016
The referendum aims to streamline Italy's cumbersome lawmaking process by reducing the powers of the Senate while also removing some key decision-making powers from regions.
Italian premier Matteo Renzi has said he will resign if the referendum fails, although how that plays out politically is likely to depend on the turnout and the margin of the decision.
Opposition politicians have vowed to press for a new government if voters reject the proposed constitutional changes.