Key points: High Court ruled Labor senator Katy Gallagher ineligible because of British citizenship

Four MPs resigned in wake of the court's decision, all from non-Government parties

The fifth by-election is for resignation of Perth MP Tim Hammond last week for family reasons

Four federal MPs have announced their resignation from Parliament after the High Court ruled Labor senator Katy Gallagher ineligible because she did not renounce her British citizenship in time. The High Court's decision puts a cloud over a number of other MPs, including first-term Labor members Susan Lamb and Justine Keay, who both hold marginal seats in outer Brisbane and western Tasmania and are possible dual British citizens. To have my place in the Senate end like this today is very deeply disappointing, but I believe that I have more to contribute to public life and I will take the time to talk with Labor Party members on how I can do this over the months ahead.”

Her disqualification opens the possibility of the same outcome for three Labor MPs and Centre Alliance’s Rebekha Sharkie.
The High Court of Australia disqualifies Senator Katy Gallagher because she held dual citizenship with the United Kingdom when elected, not renouncing it in time. Four MPs in similar situations have also resigned, setting up four by-elections.