Getting on the list was "a fairly straightforward process during lockdown and involved making a short video and providing some brief written information".
Holborow said she had some low-key involvement in the party "beginning as a volunteer in the 2010 byelection to support Kris Faafoi's first campaign".
Politically she started out on the Paekākāriki Community Board 12 years ago before becoming a councillor at Kāpiti Coast District Council.
Holborow is into her second triennium as deputy mayor under the mayoral leadership of K Gurunathan.
She felt her experience as an elected member had "given me many skills and attributes I can bring to this new position".
"My purpose has always been to serve my community in the role where I'll be of most use."
Holborow said she had decided to join the party and stand as a nominee for the Ōtaki electorate "as I believe in the work that the current Government is doing, putting people and kindness at the heart of leadership".
"I think Labour has made extremely good progress with many social and environmental issues while maintaining a strong economy and I'd like to contribute to that work."
A list MP is a Member of Parliament who is elected from a party list rather than from a geographical constituency.
Their presence in Parliament is owed to the number of votes that their party won not to votes received by the MP personally.
"The voters will determine the numbers elected from the list when they cast their party votes."
Holborow added, "There will be no impact on my ability to fulfil my role as deputy mayor in the coming months."
