Hundreds of thousands of protestors marched in Seoul for the sixth-straight week Saturday to demand the ouster and arrest of scandal-hit President Park Geun-Hye ahead of an impeachment vote in parliament.Organisers of the candlelight rally in the South Korean capital said it was the biggest protest so far with a turnout of 1.6 million. Police put the number at 320,000.

The latest in a series of massive anti-Park demonstrations came just hours after opposition parties filed an impeachment motion that will be put to a vote by lawmakers on Friday.Whether the motion is adopted or not, Park is firmly on course to become the first democratically-elected South Korean president not to complete a full, five-year term.

The 64-year-old stands accused of colluding with an old friend who has been formally indicted for attempted fraud and abuse of power.Along with the now-normal slogans for Park to step down, there were growing calls at Saturday’s rally for her to face criminal charges, arrest and imprisonment.

Dozens of life-size cardboard cut-outs of the president showed her wearing a jail uniform and bound by ropes.While the protestors want her out immediately, the political establishment is struggling to find a similar unity of purpose.

The impeachment motion introduced in the early hours of Saturday morning carried 171 signatures — accounting for every legislator from the three opposition parties and independents.In order to secure the two-thirds majority required for impeachment in the 300-seat national assembly, it will need the support of more than two-dozen lawmakers from Park’s ruling Saenuri Party.

Shifting alliances

Just a week ago, the backing of enough Saenuri rebels seemed assured, but a rather confused resignation offer by Park on Tuesday strengthened the hand of her loyalists who insist she be allowed to step down voluntarily.

The party has since proposed she resign in April — a timeline it justifies as more conducive to a calm and steady preparation for an early presidential election.Observers say the Saenuri rebels are likely to fall in line with the proposal and vote against the motion on Friday.