Four federal MPs caught up in the dual citizenship saga have resigned from parliament.
Labor MPs Justine Keay, Josh Wilson and Susan Lamb have quit.
All three held British ties at the time of the last election, meaning they're ineligible to remain in office.
Independent Rebekha Sharkie is in the same position, and says she also has no choice but to go.
Earlier today, the High Court ruled their colleague Katy Gallagher was ineligible to sit in the Senate due to her foreign ties.