Lower House member Masaru Wakasa, a close ally to Tokyo Gov. Yuriko Koike, announced Monday that he has launched a political group called Nippon First no Kai (Japan First), a development observers say could significantly change the political landscape.

The new group will hold its first rally next month with Koike attending as the main speaker.

Koike, who led Tomin First no Kai (Tokyoites First) to a landslide victory in the Tokyo Metropolitan Assembly election last month, has long been believed to be considering transitioning to national politics by forming a new party.

Wakasa’s political group — though not technically a party as defined by election laws — could be the precursor to the national party Koike has envisioned, giving her the chance to become the nation’s first female prime minister, political observers say.

Wakasa — a former member of the ruling Liberal Democratic Party who is now an independent — said that through Nippon First, he aims to form a national party that could serve as a counterbalancing political force.

Nippon First will invite individuals wishing to run in future elections, in particular the next Lower House election, to join the rally scheduled for Sept. 16, Wakasa said.

“The voice of the voters was clearly shown in the last Tokyo gubernatorial election and the Tokyo Metropolitan Assembly election,” Wakasa told a news conference in Tokyo on Monday.

“They want a new reliable party that they can turn to” beyond the LDP or the main opposition Democratic Party, Wakasa said.

According to Wakasa, Koike will not hold an executive position in Nippon First. He declined to explain what role she will play if a new national party is established.

“It’s difficult to explain that today,” he said.

According to media polls, the approval rating of Prime Minister Shinzo Abe’s Cabinet has plummeted in recent months, underlining an apparent growing frustration among voters.

At the same time, the approval ratings for opposition parties, in particular the DP, have fallen far below the 10 percent level, showing that voters still don’t see an alternative political force to challenge Abe’s LDP.

Koike’s Tomin First trounced both the LDP and the DP in the Tokyo assembly election last month, largely thanks to the frustration of voters seeking an alternative political force.

Observers say if a national party headed by Koike is formed, it could serve as a third political force and change the power balance in the Diet.

Just before the July 2 assembly election, many DP assembly members left the party to join Tomin First, a move seen by some as a desperate attempt to ensure their own political survival.

If more DP Diet members leave the party, it could trigger the complete disintegration of the largest opposition party, observers say.

Asked about Wakasa’s announcement on Monday, DP Secretary-General Yoshihiko Noda told reporters that he will “carefully keep watching” ongoing developments concerning Nippon First.

He declined to comment further, saying the details regarding Nippon First members and its policies are still unclear.