Officials are being asked how they will judge whether people claiming the right of abode are in the same situation as the 85 involved in the Court of Final Appeal test cases.
The Government has said it would not revoke the rights awarded to the 85 or any others who could prove they were in similar circumstances.
In a letter to Ian Wingfield, law officer (civil law) with the Department of Justice, Legco Secretariat legal adviser Jimmy Ma Yiu-tim asked: 'In what way and under what conditions, if any, were the two Court of Final Appeal cases regarded as 'test cases'?' Mr Ma raised the questions after Mr Wingfield appeared at a special House Committee meeting on Wednesday.
Mr Wingfield said then that permanent identity cards had been issued to more than 700 migrants involved in January's Court of Final Appeal ruling.
There was no question of their status being affected by the potential Basic Law reinterpretation, he said.
Members agreed at yesterday's House Committee meeting that they would follow up the right of abode issue at the constitutional affairs panel.