Japanese are voting in the snap election as Prime Minister Shinzo Abe is expected to get an overwhelming majority that could help him implement further economic reforms. The election has been touted as a referendum on "Abenomics".

The polling has so far been dull compared to the previous election two years ago.

Faced with a weak and splintered opposition, the governing Liberal Democratic Party (LDP) led by Abe is widely expected to sweep the polls.

The focus will be on the number of seats won by the LDP and its junior coalition partner Komeito as they bagged 326 seats in the last election.

"I have been pushing for Abenomics, the policies designed to create jobs and raise salaries. Japan can be much richer. Please let our coalition have power," Abe told a rally attended by thousands of supporters in Tokyo's neighbourhood on the eve of polling.

More than 48,000 polling stations opened at 07:00am local time and will close at 20:00. Counting will start immediately after the polling ends.

About 1,200 candidates are contesting for 475 seats in the Lower House of the Japanese parliament Diet.

"Abe's expected victory is the result of the self-destruction of the opposition. For many voters, there is no alternative but the LDP," Shinichi Nishikawa, professor of politics at Meiji University in Tokyo, told Japan Today.

Abe is seeking a fresh mandate for his economic reforms which include a hyper-easy monetary policy combined with government spending in the wake of recessionary signs.