[6][7] The vacancy was caused by the election of Senator Grace O'Sullivan to the European Parliament in May 2019.

On the formation of a new government on 27 June 2020 between Fianna Fáil, Fine Gael and the Green Party, she was appointed as Minister of State at the Department of Agriculture, Food and the Marine with responsibility for Land Use and Biodiversity.

[11] On 19 June 2024, Hackett announced her candidacy in the Green Party leadership election following the resignation of Eamon Ryan.

[13] She received several high profile endorsements, including from Brian Leddin, Ossian Smyth and Steven Matthews.

[citation needed] Hackett lives on a farm in County Offaly near Geashill with her husband Mark, whom she met at university in Essex, and their four children.