Frustration with the leadership of the main opposition Constitutional Democratic Party of Japan is growing among party members over the outcome of budget deliberations in the House of Representatives.

Although CDP leader Yoshihiko Noda declared that his party would go into "battle mode" to get its demands included in the fiscal 2025 budget bill, the Lower House on Tuesday passed a modified bill that reflects few of the demands.

Among other opposition parties, Nippon Ishin no Kai (Japan Innovation Party) and the Democratic Party for the People made their presence felt during budget deliberations in the Lower House. The CDP was "kept out of the loop as its positions were unclear," a veteran CDP member lamented.

"As the largest opposition party, we could not vote for the budget bill, but made some achievements," Noda said at a news conference on Friday.

Over the budget bill, the CDP submitted a ¥3.8-trillion amendment proposal, while focusing on attacking a government plan to raise the ceiling on out-of-pocket medical expenses.

At a news conference on Feb. 21, Noda accused the ruling coalition of putting off budget modification talks with the CDP. And at a party convention on Feb. 24, he clarified a confrontational stance against the administration, saying that his party would go into battle mode.

However, the CDP missed what Noda had described as a "crucial" opportunity at a Lower House Budget Committee meeting on Feb. 28. Noda directly urged Prime Minister Shigeru Ishiba to freeze the plan to raise the medical expense ceiling, but Ishiba only agreed to revise part of the plan.

The CDP decided not to get in the way of the Lower House's vote on the budget bill, believing that it would be impossible to delay the vote as opposition parties were divided.

Due to the CDP's lackluster performance, a party source said, "We can't compete in (this summer's) House of Councilors election if we don't do anything."

On Friday, Ishiba announced that his government had decided to cancel the plan to raise the medical expense ceiling, following his meeting with a group of patients.

"It would have been good for us if (Ishiba) had made the announcement during the Lower House deliberations," a CDP executive said.

The announcement was "too late," Noda said in a stump speech in Tokyo the same day. "It wan't a bold decision, but indecision."