The main opposition party initiated an impeachment motion against the home affairs minister, who is accused of allegedly making comments in favor of the ruling party, an opposition spokeswoman said Monday.

The New Politics Alliance for Democracy submitted the motion to the National Assembly earlier in the day, Han Jeong-ae said.

The motion is a response to a controversial toast led by Minister of Security and Public Administration Chong Jong-sup three weeks ago during a dinner with lawmakers from the ruling Saenuri Party. He allegedly asked the participants to chant "Victory at any cost" after he chanted "general elections."

South Koreans are set to go to polls next April to elect lawmakers.

The opposition party claimed Chong's comments violate national election laws that call for, among other things, the neutrality of public officials.

Chung has offered an apology over the toast while vowing to keep his job and ensure that his ministry will maintain neutrality in elections.

Kim Yong-nam, a spokesman for the ruling Saenuri Party, dismissed the opposition's move as an "excessive political offensive."

The parliament can initiate an impeachment motion against a Cabinet minister if one-third of the lawmakers endorse it. The impeachment proceedings would be referred to the Constitutional Court for a final ruling if half of the 298-strong National Assembly votes in favor.

The opposition party has 129 seats while the ruling party commands a parliamentary majority with 159 seats. (Yonhap)