The ruling Liberal Democratic Party is building its lead in the opinion polls ahead of the Upper House election, the latest survey shows.

A nationwide telephone survey conducted by Kyodo News over the weekend found that 31.1 percent of respondents intend to vote for the LDP in the proportional representation section of the House of Councilors election, up from 28.8 percent last week.

The election will be held on July 21 and campaigning is expected to kick off on Thursday.

In second place is the Democratic Party of Japan, the largest opposition force, with 7.5 percent, down from 8.2 percent last week.

In the meantime, 5.9 percent of the respondents said they intend to vote for the LDP’s coalition partner, Buddhist-backed New Komeito, little changed from 6.0 percent in the previous poll.

About 3.3 percent said they will vote for Nippon Ishin no Kai (Japan Restoration Party), co-led by former Tokyo Gov. Shintaro Ishihara and Osaka Mayor Toru Hashimoto, down from 4.8 percent.

The survey covered 1,218 eligible voters, of whom 35.5 percent said they had not decided who to vote for, down from 37.7 percent last week.

The support rate for Abe’s Cabinet meanwhile stood at 66.8 percent, up slightly from 65.6 percent in the previous survey, while its disapproval rate declined to about 22.1 percent, compared with 23.6 percent last week.