A revised bill to abolish specific political funds allocated to lawmakers for their political activities — criticized for their lack of transparency — cleared the Lower House on Tuesday, with the ongoing parliamentary session expected to be extended for three days to ensure its passage in the Upper House.

The Lower House passage of the bill, along with two other related bills, came after the ruling Liberal Democratic Party and opposition Constitutional Democratic Party of Japan struck an agreement Monday to pass the legislation in the lower chamber.

But the CDP failed to convince the LDP to include a ban on corporate donations in the bill. They will discuss the issue further over the next few months.

“We’ve agreed to vigorously debate the issue and reach a conclusion by the end of March next year,” Yuichi Goto, the CDP’s parliamentary affairs deputy chief, said Monday after the two parties came to an agreement on the bill.

This will likely prove to be a tough debate, with the LDP reluctant to ban such donations while the CDP vehemently insists on it.

Prime Minister Shigeru Ishiba told the Lower House last week that banning corporate donations would violate Article 21 of the Constitution, which guarantees freedom of speech, the press and all other forms of expression.

“It doesn’t matter whether it's an individual or a business entity. Businesses have the right to freedom of expression,” Ishiba told the lower chamber’s budget committee on Dec. 10.

But the CDP remains firmly opposed to corporate donations and continues to push for a complete ban.

The law governing what is referred to as funds for political activities became the center of debate between the ruling and opposition parties after a political slush funds scandal within the LDP led to calls for reform.

In the end, the LDP agreed to put a stop to the practice of disbursing such funds after the CDP and six other opposition parties called for their abolishment, likening them to a black box.

The LDP had pushed for a measure that would allow lawmakers to be excused from having to disclose the nature of the funds' usage when they are utilized for diplomatic and security reasons, for instance. But it decided to drop the plan after it was criticized as yet another way to make the funds opaque.

“This is a step forward for political reform,” LDP Diet Affairs Chair Tetsushi Sakamoto told reporters after Monday’s agreement with the CDP.

In addition, Tuesday saw the passage of a separate bill that establishes a third-party organization to monitor the spending of all political funds as well as a third bill that bans foreign nationals from purchasing tickets to the fundraising events of political parties.

The three bills will be taken up by the Upper House on Wednesday.

The LDP and the CDP, meanwhile, agreed Tuesday to extend the current session of parliament, originally scheduled to end on Saturday, to Tuesday next week.

Four members of a faction previously led by former Prime Minister Shinzo Abe who were implicated in the slush funds scandal also gave voluntary testimony on Tuesday to the Lower House ethics committee. They were former Defense Minister Tomomi Inada — a veteran member of the faction — as well as Ryusho Kato, Takuo Komori and Hajime Sasaki.

“I take full responsibility for the non-recording of funds at my office, and I deeply regret this,” Inada told the committee, promising to work to ensure more transparency regarding how political funds are used.

However, she noted that many Abe faction members lost their seats in the Oct. 27 general election due to the slush funds scandal, even though they were merely following orders from veteran faction leaders to refrain from reporting the funds.

On Wednesday and Thursday, the political ethics committee will also hear the testimonies of another 11 lawmakers who were members of the Abe faction, which was at the center of the scandal, as well as the faction led by former LDP Secretary-General Toshihiro Nikai.