By Luiza Ilie and Sam Cage
BUCHAREST (Reuters) - Low turnout on Sunday for a referendum to impeach suspended Romanian President Traian Basescu looked likely to derail the effort by his opponents to oust him from office.
The election bureau said turnout was 37.7 percent by 8 p.m. (1700 GMT), suggesting Prime Minister Victor Ponta's leftist Social Liberal Union (USL) would find it hard to get half the electorate to vote by the time polls close at 11 p.m.
Unless at least 50 percent of voters cast a ballot, the referendum would be invalid, setting the stage for more clashes between Basescu and his opponents in the government.
Ponta's efforts to unseat Basescu have already brought a stern dressing-down from the European Union, which accused him of undermining the rule of law and intimidating judges.
Ponta, whose government took office in May, has suspended Basescu and held the referendum to seek popular backing for his impeachment for overstepping his powers. The president is unpopular for backing austerity and for perceptions of cronyism.
Opinion polls show some 65 percent of Romanians want to remove the former sea captain from office, but the opposition had called for a boycott of the vote.
Many people were on holiday on referendum day as the temperature hit 39 C (102 F), prompting the government to set up extra polling stations, many of them at seaside restaurants and hotels, to make it easier to vote.
"Even though my wife works in the public sector and Basescu cut her salary, I will not vote and this should tell you how much I distrust the USL," said Ionut Bragan, a professional driver waiting to cross the road in Bucharest's sweltering sun.
The electoral bureau's figures have a margin of error of three percentage points and do not include Romanians voting abroad, so final turnout figures - probably due on Monday - could yet make it a close call.
Basescu initially urged Romanians to vote against what he called a coup d'etat, but this week he changed his mind and he and his allies, the opposition Democrat Liberal Party (PDL), asked supporters to boycott the referendum, citing concern about the possibility of electoral fraud.
"I voted to take him down because he cut my pension and he doesn't deserve to be in power," said Sandu Neacsu, a 66-year-old pensioner from Pantelimon near the capital Bucharest.
Romania has made progress since the 1989 overthrow of communist dictator Nicolae Ceausescu and joined the EU in 2007, but the economy slipped back into recession in the first quarter of this year and pockets of severe poverty remain.
Ponta felt the full weight of EU wrath after his government took on the Constitutional Court, threatening to replace judges and reduce its powers, and ignoring one of its decisions. Brussels said it was concerned about the government's respect for the rule of law, democratic procedures and the judiciary.
The government had tried to make it easier to impeach Basescu by removing the minimum turnout rule, but was forced to back down following harsh EU criticism and a Constitutional Court ruling that a 50 percent turnout was obligatory.
The row over Basescu has delayed policymaking, sent the leu currency plunging to record lows, and pushed up borrowing costs. It also raised concern about the future of Romania's 5 billion euro ($6.2 billion) International Monetary Fund-led aid deal.
The IMF has said it will begin a two-week review of the deal on July 31, a week later than planned because of the impeachment referendum.
Brussels has a wide range of levers with which to put pressure on Romania, whose justice system is under EU monitoring. Romania gets European cash to help it catch up with other members and the bloc contributes to its IMF-led aid deal.
Ponta promised to respect the rule of law and the independence of the judiciary, but Brussels replied that it had yet to see proof of this, for example by the replacement of a USL loyalist with a neutral figure as public ombudsman.
If Basescu is impeached, a presidential election will be held within three months. USL co-leader Crin Antonescu would remain interim president until the vote, which could delay a parliamentary election currently expected in November.
"If the referendum fails and Basescu remains president, political instability is likely to worsen," said James Goundry, analyst with IHS Global Insight.
($1 = 0.8084 euros)
(Additional reporting by Bogdan Cristel; Editing by Sophie Hares)
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