Of Ngāpuhi descent, Tau grew up in Otara, South Auckland. He went on to be involved in union organisation, community development, and early childhood education.
With a political career spanning two decades, Tau won the Northern Māori electorate in 1993 and served the following term as the Minister of Māori Affairs. After becoming a list MP in 2005, Tau also chaired the Māori Affairs Select Committee from 2008 to 2014.
Currently, Tau is a Director and Board member of Housing NZ Corporation and a Board member on the Crown Forestry Rental Trust.
Appointed to the Board representing Mataawaka, Tau is on the following Auckland Council committees:
• Civil Defence and Emergency Management