(CNN) -- Embattled Romanian President Traian Basescu declared victory late Sunday after low voter turnout appeared to doom a referendum on whether to remove him from office.
The Central Electoral Bureau estimated turnout at 45.9%, short of the majority of registered voters needed for the vote to be valid. Basescu had urged his supporters to boycott the polls, telling reporters, "The best help today is to stay home."
After the polls closed at 11 p.m. (4 p.m. ET), he said voters had rejected a "coup" by Prime Minister Victor Ponta and the interim president, Crin Antonescu. Asked if he was certain about the figures, he told them, "I'm never wrong."
Election officials' estimate was based on a survey of nearly 3,000 polling stations across the country, about 6% of the precincts. They estimated their sampling error at about 3 percentage points.
Exit polls from Romanian television stations indicated turnout was about 44% late Sunday, and that the overwhelming majority of those voting favored Basescu's impeachment. That led Ponta to say Basescu "should strongly consider whether he is still legitimate or not in the office."
"I believe that any politician that says he can ignore the voice of almost 9 million people is totally unrealistic," Ponta said.
Ponta's Social Liberal Union (USL) disputed the turnout figures, saying it had estimated 9.2 million people had voted -- slightly over 50% -- which would mean Basescu would be ousted. Final results are expected Monday.
Basescu has been suspended since the USL-led parliament voted to impeach him in early July, saying he overstepped his authority by ordering wage and benefit cuts for public workers. Basescu said the measures were needed to meet the terms of a $24 billion loan from the International Monetary Fund for the cash-strapped country, but the move soured many Romanians on his leadership.
Opponents also accuse Basescu of cronyism. He took office eight years ago and has already survived one effort to remove him, in 2007.
The latest crisis in the southeastern European nation -- slightly smaller than the U.S. state of Oregon -- has sent its currency, the leu, plummeting to record lows.
Two pro-Basescu governments have collapsed, paving the way for Ponta's center-left USL to take office. Ponta succeeded in getting lawmakers to not only suspend Basescu, but to remove both speakers of parliament and replace them with allies.
In voting Sunday, Ponta expressed anger that the prime minister of neighboring Hungary, Viktor Orban, had urged Romania's ethnic Hungarian minority not to vote.
"I want Romanians to decide their own fate," Ponta said.
Ponta is dealing with his own controversy: He has been accused of plagiarizing his doctoral thesis. He has dismissed the accusation as a political attack from Basescu.
Journalist Cosmin Stan contributed to this report.