During this period, Sharples was inspired to become more politically active, and soon after the scheme was abandoned he wrote a letter to Prime Minister Norman Kirk, explaining his reasons for opposing the plant.

[6] In 1984 Sharples led the kapa haka at the pōwhiri (opening ceremony) of the Te Maori exhibition at the Metropolitan Museum of Art in New York.

After the foreshore and seabed controversy in 2003–2004, Sharples joined forces with Tariana Turia a former minister in the Labour Party government who resigned over the issue.

In the 2005 general election Sharples contested and won the urban Auckland seat of Tamaki Makaurau displacing former Labour MP John Tamihere.

[15] In the 2015 Queen's Birthday Honours, he was appointed a Knight Companion of the New Zealand Order of Merit, for services as a Member of Parliament and to Māori.