Rival parties are likely to clash during a plenary parliamentary session Monday as the main opposition seeks to introduce a downsized budget bill for next year despite resistance from the ruling party.

The proposal, railroaded by the main opposition Democratic Party (DP) at a plenary session of the parliamentary special committee on budget and accounts last week, puts next year's budget at 677.4 trillion won ($485.3 billion), down 4.1 trillion won from the initial plan proposed by the government.

The budget cut affects the whole amount flagged for special activity expenses of the presidential office's secretariat and national security office, as well as those of the prosecution, the state audit agency and the police.

It also halves the government's 4.8 trillion-won reserve fund to 2.4 trillion won.

DP leader Park Chan-dae earlier announced plans to table the bill at the plenary session, calling it a "drastic measure" to "normalize" the country's livelihood as part of efforts to block a tax cut for the "superrich" and slash the budgets for state agencies wielding power.

The ruling People Power Party plans to hold a general meeting of its lawmakers later in the day to discuss measures to counter the DP's push.

At the plenary session, the DP will also report impeachment motions against Board of Audit and Inspection (BAI) Chair Choe Jae-hae and three top prosecutors at the Seoul Central District Prosecutors Office, including its chief Lee Chang-soo.

This marks the first time an impeachment motion against the head of the BAI has been raised in the National Assembly.

The DP took issue with Choe's refusal to comply with a parliamentary request to submit documents related to an audit of the presidential office relocation, which took place in 2022 in line with a campaign pledge of President Yoon Suk Yeol.

It also accused the three prosecutors of failing to indict first lady Kim Keon Hee despite allegations of her stock price manipulation.

The impeachment motions will be put to a vote in a plenary session of the Assembly on Wednesday. (Yonhap)