Centre Alliance MP Rebekha Sharkie and Labor MPs Justine Keay, Josh Wilson and Susan Lamb have stepped down to join Labor senator Katy Gallagher, after the High Court found Ms Gallagher ineligible to sit in the Parliament due to her dual citizenship.
Meanwhile Treasurer Scott Morrison and other government figures have been busy talking up last night's budget geared towards low- and middle-income earners,
Follow all the latest reaction live.
