PCO AI Legislative Drafting Pilot — New Zealand's generative-AI trial for explanatory notes and consolidations

New Zealand's Parliamentary Counsel Office (PCO) ran a six-month pilot testing generative AI for legislative drafting work, fine-tuning an 8-billion-parameter open language model on roughly 200 examples of New Zealand legislative text rather than adopting a large third-party model off the shelf. Five technology companies, including Catalyst IT, collaborated on the trial, with models hosted on Catalyst Cloud, New Zealand's sovereign cloud infrastructure, to keep legislative data within national jurisdiction.

Test whether generative AI could assist legislative drafters with explanatory notes, prospective consolidations of amended Acts, plain-language drafting, and a prototype chatbot for the New Zealand Legislation website — while keeping sensitive legislative data under national data-sovereignty controls.

Fine-tuned an 8B-parameter open model on ~200 NZ legislative text examples; tested the model on drafting explanatory notes for bills and generating prospective consolidations of amended Acts; prototyped a legislation-website chatbot; deployed on Catalyst Cloud sovereign infrastructure with five technology-company partners.

PCO published transparent, self-critical results pages with experiment-specific assessments rather than only promotional summaries; the practice scored 53/100 in the catalogue's evaluation (top 57% among 246 scored practices). No quantified accuracy, time-saved, or cost-saved metrics were reported.

The pilot remained an exploratory six-month trial with no production rollout or measured public-value outcomes reported yet; PCO's transparency about limitations is itself notable, but the evidence base is a self-published descriptive account rather than an independent evaluation.