The pre-election polls pit the ruling Social Liberal Union, a coalition composed of the Social Democratic Party, the National Liberal Party and the Conservative Party, against the Right Romania Alliance, whose senior partner is the opposition Liberal Democratic Party backed by President Traian Basescu.
A party has to pass a 5-percent threshold to win seats in either chamber of the parliament, while in the case of political or electoral alliances, 8 percent for alliances of two parties, 9 percent for three and 10 percent for four or more parties.
The voters are polarized following a change of the majority coalition and appointment of Social Democrat Ponta as prime minister in May.
Local elections in June gave a significant victory to the new ruling coalition which won 36 of the 41 county councils.
Opinion polls before the elections also suggested an overwhelming win for the ruling coalition.