[7] Hardy became politically active in 2011, after joining a campaign protesting against school cuts and meeting Alan Johnson, the then-MP for Kingston upon Hull West and Hessle.

She left teaching in 2015 to become a full-time organiser for the National Union of Teachers,[7] and served as Deputy General Secretary of the Socialist Educational Association before being elected to Parliament.

[8] Hardy was selected as the Labour Party's prospective parliamentary candidate for Kingston upon Hull West and Hessle after the then-MP, Alan Johnson, announced his retirement just weeks before the general election in 2017.

In October 2018, the National Institute for Health and Care Excellence (NICE) declared that vaginal mesh surgery should only be used as a "last resort" to treat pelvic organ prolapse and urinary incontinence.

[22] In January 2020, Hardy was appointed to Labour's frontbench as a Shadow Education Minister, succeeding Gordon Marsden, who lost his seat in the 2019 general election.

[31] Hardy was appointed Parliamentary Under-Secretary of State (Minister for Water and Flooding) at the Department for Environment, Food and Rural Affairs on 9 July 2024.