The Department of Justice said on Tuesday that it plans to file a judicial review seeking to strip Democracy Groundwork's Lau Siu-lai of her seat in the Legislative Council.
It has sent a letter to the High Court saying the lawsuit will be filed either this week, or early next week. It will challenge whether the council's President, Andrew Leung, had the right to give Lau a second chance to be sworn in early this month.
Lau's initial attempt, during which she read out the short oath extremely slowly, was ruled invalid by Leung. But she was sworn in successfully on her second attempt.
It is understood that the judicial review will be filed on behalf of the Chief Executive, CY Leung. He had won an earlier legal challenge over the oaths taken by two localists – Sixtus Leung and Yau Wai-ching of Youngspiration. The High Court stripped them of their seats in the council after ruling that both had effectively declined to take their oaths.
The pair then appealed and the Court of Appeal will hand down its judgment on Wednesday morning.