The result of the referendum that grants sweeping new powers to the president of Turkey is valid, the head of the electoral body says.
Sadi Guven was speaking after the main opposition Republican People’s Party (CHP) cited irregularities, including the use of unstamped ballot papers.
President Recep Tayyip Erdogan’s push for an executive presidency succeeded with just over 51% of the vote.
The win was met with both celebrations and protests across Turkey.
The CHP has demanded a recount of 60% of the votes.
But Mr Guven told reporters on Monday the unstamped ballot papers had been produced by the High Electoral Board and were valid.
He said a similar procedure had been used in past elections.
Three of Turkey’s biggest cities – Istanbul, Ankara and Izmir – all voted No to the constitutional changes.
Opposition supporters took to the streets of Istanbul to bang pots and pans – a traditional form of protest – in a series of noisy demonstrations.
Meanwhile, flag-waving supporters of Mr Erdogan celebrated as their president praised them for their “historic decision” that could keep him in office until 2029.
With 99.97% of ballots counted, the Yes campaign had won 51.41% of the votes cast, while No had taken 48.59%. Turnout was said to be as high as 85%.
Deputy Prime Minister Mehmet Simsek said there would be no early elections following the result.
The parliamentary vote would be held as scheduled in 2019, Mr Simsek told Reuters news agency.
Responding to Sunday’s result, the European Commission issued a statement saying it was awaiting the assessment of international observers.
It urged Mr Erdogan to respect the closeness of the vote and to “seek the broadest possible national consensus” when considering the far-reaching implications of the constitutional amendments.
A similar call was made by Chancellor Angela Merkel of Germany.
“The tight referendum result shows how deeply divided Turkish society is and that means a big responsibility for the Turkish leadership and for President Erdogan personally,” Mrs Merkel said in a joint statement with Foreign Minister Sigmar Gabriel.
Profoundly polarised – BBC’s Mark Lowen in Ankara
A divisive campaign ended in a contested result. President Erdogan declared victory by a narrow margin and called on every side to respect it. But the opposition has not conceded, claiming voting irregularities. It’s clouded the legitimacy of the mandate the president now feels he’s been given, to concentrate political power in his hands.
International observers will give their verdict today – that could embolden or weaken the opposition’s case and determine how Turkey’s western allies will respond.
Mr Erdogan hoped this would be the crowning moment of his career. But it’s left Turkey profoundly polarised, at risk of becoming another chronically unstable part of the Middle East.
Death penalty next?
“Today… Turkey has taken a historic decision,” Mr Erdogan told reporters at his official Istanbul residence, the Huber Palace. “With the people, we have realised the most important reform in our history.”
The president also said the country could hold a referendum on bringing back the death penalty – a move that would end Turkey’s EU negotiations.
What’s in the new constitution?
The draft states that the next presidential and parliamentary elections will be held on 3 November 2019.
The president will have a five-year tenure, for a maximum of two terms.
- The president will be able to directly appoint top public officials, including ministers
- He will also be able to assign one or several vice-presidents
- The job of prime minister, currently held by Binali Yildirim, will be scrapped
- The president will have power to intervene in the judiciary, which Mr Erdogan has accused of being influenced by Fethullah Gulen, the Pennsylvania-based preacher he blames for the failed coup in July
- The president will decide whether or not impose a state of emergency
Mr Erdogan says the changes are needed to address Turkey’s security challenges nine months after an attempted coup, and to avoid the fragile coalition governments of the past.
The new system, he argues, will resemble those in France and the US and will bring calm in a time of turmoil marked by a Kurdish insurgency, Islamist militancy and conflict in neighbouring Syria, which has led to a huge refugee influx.
Critics of the changes fear the move will make the president’s position too powerful, arguing that it amounts to one-man rule, without the checks and balances of other presidential systems such as those in France and the US.
They say his ability to retain ties to a political party – Mr Erdogan could resume leadership of the AKP he co-founded – will end any chance of impartiality.
CHP deputy leader Erdal Aksunger said he believed there had been irregularities in the count: “Many illegal acts are being carried out in favour of the Yes campaign right now.
“There is the state on one side and people on the other. No will win in the end. Everybody will see that.”
The pro-Kurdish Peoples’ Democratic Party (HDP) also challenged the vote.
Many Turks already fear growing authoritarianism in their country, where tens of thousands of people have been arrested, and at least 100,000 sacked or suspended from their jobs, since a coup attempt last July.
The campaign unfolded under a state of emergency imposed in the wake of the failed coup.
Mr Erdogan assumed the presidency, meant to be a largely ceremonial position, in 2014 after more than a decade as prime minister.
Under his rule, the middle class has ballooned and infrastructure has been modernised, while religious Turks have been empowered.
Relations with the EU, meanwhile, have deteriorated. Mr Erdogan sparred bitterly with European governments who banned rallies by his ministers in their countries during the referendum campaign. He called the bans “Nazi acts”.