South Korea's opposition leader gains ground on presidency / South Korea's opposition-controlled parliament votes to impeach acting president / South Korea's opposition-controlled National Assembly votes to impeach acting President Han / South Korea's opposition-controlled National Assembly votes to impeach acting leader Han / South Korea's opposition moves to impeach acting President Han / South Korea's opposition moves to impeach acting president / South Korean opposition submits motion to impeach the country's acting president as strife deepens / South Korea's opposition moves to impeach acting President Han Duck-soo