The approval rate for Prime Minister Shinzo Abe's Cabinet fell to 36.7 percent, a Kyodo News survey showed Sunday.
The result follows the arrests of former Justice Minister Katsuyuki Kawai and his lawmaker wife on Thursday for alleged vote buying in an Upper House election last year in which she won her Diet seat. Kawai is known for his close ties with Abe.
The approval rate dropped from 39.4 percent in the previous survey held late last month.
In the two-day survey that began Saturday, 90.4 percent said Kawai and his wife, Anri, should quit as lawmakers. The couple left the ruling Liberal Democratic Party just before the arrests but have kept their seats in the Lower and Upper Houses, respectively.
The survey also found that a total of 75.9 percent of respondents believe Abe to be significantly or to some extent responsible for confusion over the scandal.
