Aiming to provide a counterbalance to the sweeping rise of conservative forces in Japan’s political arena, a former Democratic Party lawmaker announced Monday he will establish a new liberal-minded party to maximize the chances of dethroning Prime Minister Shinzo Abe.

Yukio Edano, an eight-term lawmaker, said he will head the new party, which will be named Rikken Minshu To. This roughly translates as Party of Constitutionalism and Democracy.

“I’ve decided to found this new party to protect the livelihood of Japanese people, constitutionalism, democracy and their free society,” Edano, 53, told a packed news conference. “I hope the public will support our bid to put a stop to the Abe administration, which is spiraling out of control.”

The formation of the party could change the dynamics of what was shaping up to be a two-way race in the Oct. 22 election, in which Abe’s ruling bloc and Tokyo Gov. Yuriko Koike’s upstart Kibo no To (Party of Hope) — both conservative — were expected to vie for power.

His move also comes as the DP, long mired in abysmally low approval ratings of less than 10 percent, was on the verge of disintegrating.

Last week, DP head Seiji Maehara and Koike agreed that DP members — assuming they hold the same position as Koike on constitutional revision and beefing up national security — would be allowed to merge with her fledgling party and run on its general election ticket.

The arrangement will involve the DP refraining from fielding candidates in the race, effectively leading to the nation’s largest opposition party disbanding its Lower House caucus.

Edano’s move also comes as left-leaning members of the DP find their presence increasingly dwarfed by the populist Koike as she wages what could be described as an anti-liberal crusade by pointedly rejecting their migration into her party.

When asked last week whether she was planning to “massacre” the DP’s liberal lawmakers by not granting them Kibo no To membership, a smiling Koike made no secret of her intention to screen them out, nonchalantly saying she will “get rid of” them.

Koike’s plan to filter out those considered too left-leaning is expected to result in 60 to 70 DP candidates ending up adrift, forcing them to run as independents or seek fresh backing from Edano’s new party. In a worst-case scenario, they may have to give up on running altogether.

On Monday, Koike’s party was scheduled to reveal the lineup of its first batch of candidates, but that announcement was delayed until Tuesday.

Edano, for his part, said that while Koike shares with him the goal of booting Abe from power, he finds her party fundamentally incompatible in terms of policy and ideology.

The two emerging forces, he said, are on the same page in demanding that the planned 2019 consumption tax hike be shelved and Japan’s dependence on nuclear power be slashed to zero. But he said his new ﻿﻿party will consider the security laws steamrolled through the Diet by the Abe-led ruling bloc in 2015 “unconstitutional,” while Kibo no To upholds the legislation.

Edano, however, said he is not mulling a tie-up with other opposition parties, including the Japanese Communist Party or the Liberal Party, but sounded a hopeful note that he may seek cooperation from citizens’ groups similarly dismayed by Abe’s rise.

Edano declined to reveal which lawmakers may be joining his party, saying details have yet to be fleshed out.

Meanwhile, several DP heavyweights announced they will throw their hats into the ring as independents this time around.

These include former Prime Minister Yoshihiko Noda and former Foreign Minister Katsuya Okada, who had also served as president of the DP and its predecessor, the Democratic Party of Japan.

Speaking to reporters Monday, Okada said he doesn’t intend to join Koike’s new party because he thinks a Japan ruled by two conservative parties does not provide voters with a real alternative to Abe’s LDP. At the same time, however, Okada also said Edano’s new liberal-minded party is not 100 percent in keeping with his political ideology, either.