OSAKA – As Nippon Ishin no Kai (Japan Restoration Party) gears up for this summer’s Upper House election, its relationship with New Komeito, especially over constitutional revision, has come under increased pressure.

Last week, Nippon Ishin unveiled its basic policy outline for the campaign. At the top of the list was revision of Article 96 of the Constitution, which requires constitutional amendments be passed by a two-thirds majority in both Diet chambers.

Like Prime Minister Shinzo Abe, who heads the ruling Liberal Democratic Party, Nippon Ishin supports changing the requirement to a simple majority in both houses. Party leader Shintaro Ishihara has aggressively pushed for this revision because, like Abe, he sees it as the main roadblock to revising Article 9, the war-renouncing clause. Buddhist-backed New Komeito opposes revising Article 9.

“The focus (in the election) will be the Constitution,” Ishihara said Tuesday in Tokyo.

But Osaka Mayor Toru Hashimoto, who serves as Nippon Ishin’s coleader, and the western faction of the party have taken a slightly less aggressive view due to concerns among Osaka-based members about New Komeito.

Since becoming Osaka mayor in November 2011, Hashimoto, whose local Osaka Ishin no Kai group won 33 of the 86 municipal assembly seats, has formed a coalition with New Komeito, which has 19 seats, to get legislation passed.

However, the coalition is not merely for the sake of reaching a majority. Hashimoto relies heavily on the advice of more experienced New Komeito members to govern Osaka and is at personal odds with the local chapter of the LDP, which is in the opposition camp in both the municipal and prefectural assemblies.

But since the Lower House election and return of the LDP-New Komeito ruling coalition at the national level, Nippon Ishin’s relationship with New Komeito has become more strained.

New Komeito joined with the LDP in the Osaka Municipal Assembly last week to vote to postpone discussions about privatizing the Osaka subway system, long a key Hashimoto goal. Then, at Nippon Ishin’s convention, Ishihara criticized New Komeito’s stance on constitutional revision.

Hashimoto reminded Ishihara via a live video discussion that New Komeito’s cooperation in the municipal assembly was necessary for his party to get its legislation passed.

On Tuesday, even as Ishihara said the Constitution would be the main issue of the Upper House election, New Komeito leaders were sounding a very different note on revising Article 96.

“We haven’t been able to reach a consensus with the people regarding the value and meaning of raising and debating the revision of just one article,” said New Komeito leader Natsuo Yamaguchi.

Hashimoto has gone out of his way to praise Abe’s leadership, leading to speculation that once the Upper House election is over the LDP and Nippon Ishin could tie up, especially if the two parties combined would form a two-thirds supermajority.

Hashimoto has made it clear that Nippon Ishin hopes it and the LDP could form the necessary two-thirds majority to revise Article 96.

However, he is also concerned that other key Nippon Ishin goals, especially achieving greater regional autonomy and increased privatization efforts, would be squelched by the LDP if the two parties had a formal alliance.