Public support for Japanese Prime Minister Shinzo Abe has fallen to the lowest level of his premiership, opinion polls showed Monday, after scandals and a historic defeat of his ruling party in Tokyo elections.

Abe took power in December 2012 on the back of widespread frustration with the previous administration's handling of the March 2011 nuclear disaster and a faltering economy which he vowed to revive.

But his Liberal Democratic Party (LDP) suffered a drubbing in a July 2 vote for Tokyo's municipal assembly that media and analysts chalked up to a growing perception of "arrogance" on the part of his government.

The party lost more than half of its seats, with the result seen as a bellwether for national political sentiment.

For months Abe has been dogged by scandals, most recently claims he showed favouritism to a friend in a business deal, an accusation he denies.

Voter support for Abe's cabinet dropped five percentage points in just a week to 33 percent according to the latest poll of more than 2,000 voters by the liberal Asahi Shimbun, marking the lowest level since he took office more than four years ago.

Among those who disapproved of Abe, 95 percent were critical of how he addressed the favoritism scandal.