The Japanese government is considering convening an extraordinary parliamentary session on Oct. 4 to choose Prime Minister Yoshihide Suga's successor, sources said Tuesday as the race among hopefuls in the ruling Liberal Democratic Party heated up.

The winner of the LDP's leadership race on Sept. 29 is set to be voted in as prime minister as the party and its junior coalition partner Komeito control the powerful House of Representatives.

Suga abruptly announced his resignation last week after less than a year in office amid mounting criticism over his COVID-19 response.

If the extraordinary session is called on Oct. 4 and the new prime minister delivers a policy speech as is customary in the same week with questioning from opposition leaders the following week, the upcoming general election could be held as early as Nov. 7.

Contenders in the LDP leadership race, including former Foreign Minister Fumio Kishida and vaccine chief Taro Kono, continued their preparations Tuesday for the LDP leadership race, talking strategy with lawmaker allies as they look to build support.

Former communications minister Sanae Takaichi is expected to announce her bid in a press conference on Wednesday, while former Defense Minister Shigeru Ishiba is still on the fence.

Ishiba had long been considered a contender to become prime minister but suffered a loss in momentum after placing third behind Suga and Kishida in last September's LDP leadership race.

Some people close to Ishiba are urging him to run again, while others see his chances of winning as slim and are instead pushing him to back Kono, who consistently places high in opinion polls on who is most fit to become prime minister.

Meanwhile, the main opposition Constitutional Democratic Party of Japan unveiled its campaign pledges for the general election on Tuesday, vowing to draw up a supplementary budget worth at least 30 trillion yen ($270 billion) to support people and businesses hit hard by the pandemic.

If voted into power, the CDPJ will also create a new team answering directly to the prime minister to steer the government's COVID-19 response, leader Yukio Edano told a press conference.

The CDPJ and three other opposition groups -- the Japanese Communist Party, the Social Democratic Party and Reiwa Shinsengumi -- are set to agree on a set of joint pledges on Wednesday including lowering the consumption tax rate and phasing out nuclear energy.

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