In the 1990s, Spence worked as a political researcher in the Labour Research Unit of the New Zealand parliament, speechwriter, journalist and lobbyist in New Zealand and was also the lead singer and frontman in a popular rock band called Edge with his younger brother . In 1997, Spence became the youngest ever Executive Director of the New Zealand Drug Foundation, a public health advocacy/lobby group. Spence led intensive communications and public relations work, policy development and political lobbying, taking a public health perspective, on behalf of the drug and alcohol sector. This involved developing media campaigns, being a public spokesperson, and leading the development of research-based advocacy work. He also co-hosted a successful drug education conference and launched a popular website.