South Korea’s opposition parties are scrambling to get as many ruling party lawmakers as possible to support its upcoming campaign to impeach President Park Geun-hye.

The three parties -- the Democratic Party of Korea, People’s Party and Justice Party -- have decided to present a parliamentary motion to remove Park from office. At least 29 votes from across the aisle are required for it to be passed.

“As soon as we meet the quorum, we will present the impeachment motion,” floor leader Rep. Woo Sang-ho of the main opposition Democratic Party said Tuesday.

A substantial number of Saenuri Party lawmakers have been speaking out against the embattled president, but the Democratic Party is not sure how many of them would actually cast ballots for her impeachment, Rep. Woo said. President Park is a member of Saenuri and the party’s top decision-making leadership council is controlled by politicians still loyal to her.

“Some say it would be at least 40 (votes), while some say even 30 is a number that can only be imagined,” he said.

To submit the motion to the National Assembly, the opposition must first obtain signatures from 150 lawmakers of the total 300.

For the motion to make it pass the parliament, at least 200 lawmakers have to agree. Currently, the three opposition parties and liberal-minded independents have 171 votes.

Opposition parties expect that the campaign to gather lawmakers’ signatures for the motion will provide some clarity as to how many votes will come from Saenuri.

The Democratic Party announced Sunday they would form a committee to oversee the impeachment process, while the People’s Party said it would negotiate with dissenting Saenuri members to vote for an impeachment.

Rep. Kim Han-jung of the Democratic Party made a proposal to hold an open vote for the impeachment citing citizens’ right to know. However, vice floor leader Rep. Park Wan-ju expressed concern and said that a secret ballot may be more helpful in getting votes from Saenuri members.

Political observers say the parties may present the impeachment motion to the parliament after the mass anti-Park candlelight vigil expected to take place Saturday.

Some 1 million citizens took to the streets of Seoul on Nov. 12, while slightly less than a million people protested all around the country Saturday, according to the rally organizers.

By Jo He-rim (herim@heraldcorp.com)