| Sergei Stanishev, the leader of opposition BSP-Bulgarian Socialist Party and front-runner in general elections |
About eight percent of the country's 6.7 million eligible voters had cast their ballots in the first four hours.
Opinion polls indicate the Socialists, the country's former Communists, will get at least 35 percent of the vote. Prime Minister Simeon Saxe-Coburg-Gotha's Simeon II National Movement is forecast to win about 20 percent.
A Socialist victory would continue a 15-year trend in post-Communist Bulgaria in which no government has won re-election.
Mr. Saxe-Coburg-Gotha, who was Bulgaria's king as a child, has managed to increase economic growth and sharply cut unemployment since assuming office in 2001. However, many average voters remain disappointed over his failure to fully revive the country's economy and deal with crime and other domestic issues.
Some information for this report provided by AFP, AP and Reuters.