The ruling Liberal Democratic Party is the most popular political group among voters ahead of the general election, though nearly 40% remain undecided on which party they will vote for, a Kyodo News survey showed Sunday.

In the nationwide telephone survey conducted on Saturday and Sunday, 29.6% of respondents said they will vote for the LDP led by Prime Minister Fumio Kishida when casting ballots under proportional representation on Oct. 31, followed by 9.7% backing the main opposition Constitutional Democratic Party of Japan.

But 39.4% said they still do not know which party they will vote for. The LDP's junior coalition partner Komeito was supported by 4.7%.