Japan's Prime Minister Fumio Kishida

 Japan's reconstruction minister resigned on Tuesday over alleged financial improprieties, becoming the fourth minister to depart Prime Minister Fumio Kishida's cabinet in just three months.

Reconstruction Minister Kenya Akiba, who is under fire over alleged illegal political payments to his aides, wife and mother, told reporters: "I believe there is no illegality in terms of my actions."

But "it is not my wish to see proceedings for the budget and other legislative agendas stall," he added.

His resignation comes as Kishida battles some of the lowest approval ratings of his tenure.

The public has become increasingly disillusioned with his cabinet after a string of scandals and revelations about ties between lawmakers and the Unification Church sect.

Akiba's firing comes after the minister for internal affairs resigned in November over alleged campaign finance irregularities. That departure was preceded by the resignation of the justice minister, who stepped down after reportedly saying his "low-profile" job only generated media coverage when approving death penalty sentences.

And in October, the minister for economic revitalization resigned over allegations of ties to the Unification Church.

The sect has been in the spotlight since reports emerged that the man accused of killing former prime minister Shinzo Abe resented the organization over donations his mother made that bankrupted the family.

The church, officially known as the Family Federation for World Peace and Unification, has denied wrongdoing.

Approval ratings for Kishida's cabinet have been hovering near the so-called "danger level" of 30 percent, and there has been speculation he could reshuffle his cabinet before the next parliament session opens in January.