Japan's parliament on Wednesday formally re-elected Shinzo Abe as prime minister after his party's crushing election victory, setting the 63-year-old on track to become the country's longest-serving premier.

MPs voted by a huge majority to re-install Abe, after his conservative Liberal Democratic Party (LDP) swept to a two-thirds "super majority" on October 22.

During the campaign Abe had stressed the need for strong leadership to deal with what he called Japan's "twin crises", a belligerent and nuclear-armed North Korea and a shrinking birth rate.

He has also vowed to start a debate on the controversial issue of making changes to Japan's US-imposed post-war constitution to bolster the role of the military in the formally pacifist country.

In the 465-seat lower house, Abe won 312 votes from the conservative ruling bloc.

In the 242-seat upper house, Abe won a majority vote of 151 votes, returning him to the top Japanese political post.

"Our chamber nominates Mr Shinzo Abe as the prime minister," lower house speaker Tadamori Oshima declared after the televised vote.

A beaming Abe then moved around the chamber, shaking hands with supporters.

Despite his overwhelming victory in the October polls, Abe's popularity ratings are relatively low and most observers attribute his election success to a weak and fractured opposition.

The main opposition party, the Democratic Party (DP), effectively disbanded after Tokyo Governor Yuriko Koike launched a new conservative group and vowed to do away with "old school politics".

Several DP lawmakers defected to Koike's new "Party of Hope" and the more left-leaning MPs formed a new party, the Constitutional Democrats.

In the end, Koike's support imploded, mainly because she failed to stand herself in the election -- confusing voters who did not know who would be premier if she won.

The Party of Hope finished with a mere 50 seats while the Constitutional Democrats won 55.

They were both dwarfed by Abe's conservative coalition, which secured 313 lower house seats and obtained the "super majority" required to change the constitution.