Japanese Communist Party leader Kazuo Shii speaks during a debate at Japan National Press Club in Tokyo on July 3.European Pressphoto Agency

Building on electoral successes earlier this year, Japan's oldest political party can now claim to be the country's number-two party -- in popularity if not in seats.

In a telephone survey of 902 voters over the weekend by the Nikkei and TV Tokyo, the Japanese Communist Party garnered a support rating of 6%. While modest compared with an overwhelming 55% for the ruling Liberal Democratic Party, it was the JCP's highest support level in the poll since 2001.

The result follows a pair of victories for the nearly century-old JCP, which had slowly been losing ground in recent years.

First, in the Tokyo Metropolitan Assembly election in June -- seen as a litmus test for national support levels -- the JCP more than doubled the number of its seats to 17 from eight previously.

Then, amid a push to update its image with a sleek online campaign and some risqué cartoon characters, the party increased its seats in the July upper house election to 11 from six, the first increase since 1998.

Political analysts say the Communists' surge in support was linked to a plunge in support for previously popular opposition parties, such as the Democratic Party of Japan and the Japan Restoration Party.

The JCP's showing in the Nikkei poll -- which didn't give a margin of error -- put it a full percentage point ahead of the DPJ, which lost power to the LDP in national elections late last year. The JCP was also two percentage points ahead of Osaka Mayor Toru Hashimoto's upstart Japan Restoration Party. Of those who responded to the poll, 19% said they didn't support any specific party.

Support for all opposition parties combined, however, wasn't even half that of the LDP's 55%.

"I think that many people have a sense of crisis and anxiety that the Liberal Democratic Party's politics may be dangerous," JCP head Kazuo Shii said in explaining the party's July electoral success.

He added that the JCP had won the "people's approval" for its commitment to raising incomes, getting rid of nuclear power and preserving the country's constitution.

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