[5] Willis contested the Taieri electorate in the 2020 election, when he came third to Labour MP Ingrid Leary and National Party candidate Liam Kernaghan, with 2207 votes.

[12] At the campaign launch in June, Willis said "We need a strong voice on the hospital build and our health services; for all whānau living in cold, damp mouldy homes; for our tertiary education – our University and Te Pukenga.

We need a strong voice and forward thinking for South Dunedin and our rural and energy sectors, for decarbonising to deliver climate justice.

"[10] During the 2023 election, Willis received 3,898 votes in Taeiri, coming third to incumbent Ingrid Leary and National Party candidate Matthew French.

[14][7] In late November, Willis assumed the Green Party's energy, regional development, rural communities and Dunedin Issues spokesperson portfolios.