Polling stations are open in Romania for parliamentary elections.
Opinion polls suggest a win for the governing coalition led by Prime Minister Victor Ponta.
But the result could trigger renewed political instability as Romania negotiates a vital loan agreement with the International Monetary Fund.
Mr Ponta and President Traian Basescu have been bitter enemies since the government tried to impeach the president in July.
In the event of Mr Ponta's party winning, the president may ask someone other than him to form a government.
A BBC correspondent says any attempt to appoint someone else may result in a constitutional crisis.
If the Social Liberal Union (USL) falls short of a majority, Mr Basescu could ask one of his allies in the Right Romania Alliance (ARD) to try to form a coalition. Opinion polls have put the ARD in second place.