Nearly 30% of voters plan to cast ballots for Japan's ruling Liberal Democratic Party in the proportional representation section of Sunday's general election, compared with just over 11% for the main opposition Constitutional Democratic Party of Japan (CDP), according to the latest Kyodo News survey.

But the most, nearly 36%, said they were undecided on which party to vote for in the election.

For voting by constituency, about 36% preferred a candidate from the LDP-led coalition, while nearly 20% expressed support for one backed by opposition parties.