[5] While in the seventh form, she was selected to represent Rongotai MP Annette King as a member of the third New Zealand Youth Parliament in 2000.

[11] There, she won acclaim for her role in winning a high-profile case in the Court of Justice of the European Union about safe working hours.

[17] The bill was described as "controversial" because it failed to receive select committee support, was perceived to increase the risk of litigation for companies and directors, and because it imposed no new obligations.

[20] Ahead of the 2023 general election, Belich sought to succeed retiring former prime minister Jacinda Ardern in the safe Labour electorate of Mount Albert.

Despite having Ardern's personal support,[4][21] Belich missed out with fellow list MP Helen White winning the selection.

[24][25][26] She assumed the junior whip, workplace relations and safety, and emergency management portfolios in the Shadow Cabinet of Chris Hipkins.