ANKARA, Turkey — Turkey's main opposition party urged the country's electoral board Monday to cancel the results of a landmark referendum that granted sweeping new powers to the nation's president, citing what it called substantial voting irregularities.
Turkey's electoral board confirmed the "yes" victory in the referendum and said the final results would be declared in 11-12 days. The state-run Anadolu Agency said the "yes" side stood at 51.4 percent of the vote, while the "no" vote saw 48.6 percent support.
The margin fell short of the sweeping victory that President Recep Tayyip Erdogan had sought. Nevertheless, it could cement his hold on power in Turkey for a decade and is expected to have a huge effect on the country's long-term political future and its international relations.
"I suspect the result was narrower than what Erdogan expected," said Howard Eissenstat, associate professor of Middle East History at St. Lawrence University in Canton, New York. "Erdogan has ruled with a narrow victory before. He does not see a narrow victory as anything less than a mandate. His tendency has been not to co-opt the opposition but to crush it."
Erdogan, 63, initially sounded a conciliatory tone in his remarks, saying the result was a victory not just for those who voted "yes," but for "the whole 80 million, the whole of Turkey."
But his more abrasive style quickly returned.
"There are those who are belittling the result. They shouldn't try, it will be in vain," he told cheering, flag-waving supporters in Istanbul. "It's too late now."
Opposition parties still cried foul. Bulent Tezcan, deputy chairman of the Republican People's Party, or CHP, cited numerous problems in the conduct of the vote.
An unprecedented electoral board decision to accept as valid ballots that didn't bear the official stamp has led to outrage.
Normally for a ballot to be considered valid, it must bear the official stamp on the back, be put into an envelope that also bears an official stamp and be handed to the voter by an electoral official at a polling station. The system is designed to ensure that only one vote is cast per registered person and to avoid the possibility of ballot box-stuffing.
The board announced Sunday, however, that it would accept unstamped envelopes as valid after many voters complained about being handed blank envelopes that did not bear the official stamp. The board said the ballot papers would be considered invalid only if it was proven they were fraudulently cast.
"There is only one way to end the discussions about the vote's legitimacy and to put the people at ease, and that is for the Supreme Electoral Board to cancel the vote," Tezcan said.
He said it was not possible for authorities to determine how many ballot papers may have been irregularly cast.
Electoral board head Sadi Guven rejected opposition claims of foul play, saying none of the ballot papers declared valid was "fake" or fraudulently cast. Guven said the decision was made so that voters who were by mistake given unstamped ballot papers would not be "victimized."
"The ballot papers are not fake, there is no (reason) for doubt," Guven said.
Tezcan said any decision that changes Turkey's political system to such a vast extent should have been passed with an overwhelming endorsement.
"This is not a text of social consensus but one of social division," Tezcan said. "There is a serious and solid problem of legitimacy that will forever be debated."
The referendum approves 18 constitutional amendments that will replace Turkey's parliamentary system of governance with a presidential one.
The changes allow the president to appoint ministers, senior government officials and half the members of Turkey's highest judicial body, as well as to issue decrees and declare states of emergency. They set a limit of two five-year terms for presidents.
The new presidential system takes effect at the next election, currently slated for 2019. Other changes will take effect sooner, including an amendment that scraps a clause requiring the president to be impartial, allowing Erdogan to regain membership of the ruling party he founded — or even to lead it.
Opponents had argued the constitutional changes give too much power to a man who they say has shown increasingly autocratic tendencies.
The referendum campaign was highly divisive and heavily one-sided, with the "yes" side dominating the airwaves and billboards. Supporters of the "no" vote complained of intimidation, including beatings, detentions and threats.
CHP legislator Utku Cakirozer told The Associated Press his party would file official objections Monday to results at local electoral board branches, before taking their case to the Supreme Electoral Board.
"At the moment, this is a dubious vote," he said.
The country's pro-Kurdish party said it may take the case to the European Court of Human Rights if the electoral board does not reverse its decision and nullify the ballots lacking the official stamps.
The Organization for Security and Cooperation in Europe, whose monitors observed Sunday's vote, were to announce their findings later Monday.
Ismail Calisan, an Ankara resident, accepted the result with grace.
"Even though I choose "no" and the results came out "yes," I wish the best to our country," he said.
In Istanbul, accountant Mete Cetinkaya was worried about his country's future.
"I don't see the country is going down a good path," he said, sitting by the Bosporus. "Tayyip Erdogan may have done more good than the other big players (of Turkish politics) ... but I think of Tayyip Erdogan as just the best of the worst."
Becatoros contributed from Istanbul contributed to this report.