Japan's main opposition Constitutional Democratic Party of Japan and the smaller Democratic Party for the People agreed Friday that their leaders would meet next week to explore coordination over political reforms and other priorities.

The agreement reached by the secretaries general of the two parties marks a turnaround from the DPP's earlier rejection of a CDPJ offer to arrange a top-level meeting ahead of a parliamentary vote to choose a prime minister after the ruling bloc lost its majority in the powerful House of Representatives in Sunday's general election.

The DPP, which has grown in influence after its seats quadrupled in the lower house, had said it was not interested in a meeting if it was designed for the CDPJ to rally support for its leader Yoshihiko Noda's bid for the premiership. The DPP plans to vote for its own leader Yuichiro Tamaki when parliament holds a vote, possibly on Nov 11.

During Friday's meeting, the CDPJ and the DPP secretaries general agreed on the need to continue discussions on key issues where their stances diverge, including constitutional reforms and the use of nuclear power.

The agreement comes in response to a request by the two parties' major support group Rengo, the umbrella organization of labor unions, to hash out policy differences and cooperate in opposing the ruling camp.

The ruling coalition of the Liberal Democratic Party led by Prime Minister Shigeru Ishiba and the Komeito party is also courting the DPP for support in allowing them to run a minority government and pass bills.

After meeting with his CDPJ counterpart, DPP Secretary General Kazuya Shimba said his party will proceed with policy coordination by "keeping the same distance" from both the CDPJ and LDP.

If no party leader is able to secure a majority in the initial vote for prime minister in parliament, a runoff will be held between the two top candidates, who are expected to be Ishiba and Noda.

CDPJ chief Noda said Friday he wants to discuss a range of issues with the DPP chief, not limited to political reforms in the wake of a slush funds scandal that hit the LDP late last year.

"I want to discuss a range of issues with him, including Diet reforms and the issue of the income barrier of 1.03 million yen," Noda told a press conference.

At the forefront of the DPP's policy push is to increase people's incomes at a time of rising prices.

Its leader Tamaki said Thursday he will continue to aim for raising the income threshold for people to start paying taxes from the current 1.03 million, signaling that taking up the issue will be a requisite for the DPP to cooperate with the LDP.