Turkey’s President Recep Tayyip Erdogan has rejected criticism by monitors who say the referendum campaign fell short of international standards.
“Know your place,” he said, adding that he did not accept the comments. The observers said Mr Erdogan had been favoured by an “unequal” campaign.
The narrow vote was ruled valid by Turkey’s electoral body, despite claims of irregularities by the opposition.
Meanwhile, the country has extended the state of emergency for three months.
The measure, introduced after a failed coup last July, was set to expire in two days.
The decision comes the day after Mr Erdogan’s push for an executive presidency succeeded with 51.4% voting for it.
Monitors: ‘Unlevel playing field’
Despite saying that the voting day was “well administered”, the Organization for Security and Co-operation in Europe (OSCE) and the Council of Europe criticised the campaign, saying:
“In general, the referendum did not live up to Council of Europe standards,” said Cezar Florin Preda, head of the Council of Europe delegation.
The council is a pan-European human rights body of which Turkey is a member.
The monitors also criticised a late change by electoral officials that allowed voting papers without official stamps to be counted. They said this move “removed an important safeguard and were contested by the opposition.
But the head of Turkey’s electoral body, Sadi Guven, said 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.
Earlier, Turkey’s foreign ministry said the remarks by the monitors lacked impartiality. “Saying the referendum fell below international standards is unacceptable,” it said in a statement.
The main opposition Republican People’s Party (CHP) has demanded a recount of 60% of the votes. Its deputy head said the result should be annulled altogether.
The pro-Kurdish Peoples’ Democratic Party (HDP) also challenged the vote.
What now? By Mark Lowen, BBC News, Ankara
This was a damning verdict by the observer mission.
From biased media coverage to a misuse of administrative resources by the president and government; and from restrictions on free speech to a decision to accept unstamped ballots, which “contradicted the law”; the election observers concluded that the referendum did not fulfil international standards. So what now?
It’s sure to embolden the opposition in its attempts to challenge the results. But that is an uphill struggle in a country where the state machinery is so heavily controlled by the president and his inner circle and where around 80% of the media is pro-government, pushing its interpretation of the facts.
What’s more certain is that it’ll shape the response to the referendum by European leaders and officials. They won’t rush to congratulate a victory whose legitimacy has been placed in serious doubt. And as government supporters double down, convinced of their win, the chasm between Turkey and the west shows no sign of narrowing.
Turnout for the divisive vote was high – 85%. Mr Erdogan won in his central Anatolian heartland and on the Black Sea coast.
But he lost in the districts containing Turkey’s three largest cities.
In Istanbul, the largest city, and the capital, Ankara, the vote was very close. But in Izmir, the third-largest city, the margin was a much higher 68.8% No.
Along the Aegean and Southeast Anatolia coast – which is home to many Kurds – most districts also rejected the changes.
The constitutional changes
Addressing supporters in the presidential palace in Ankara, Mr Erdogan said that Turkey did not “see, hear or acknowledge the politically motivated reports” of the monitors.
The result, he said, ended the debate on changing the constitution and creating an executive presidency, adding that the process of implementing the reforms would now begin.
He also said the country could hold a referendum on its long-stalled EU membership bid.
Additionally, Mr Erdogan said he would approve the death penalty if it was supported in a referendum or a bill was submitted to him through parliament. This would end Turkey’s EU negotiations.