He was Leader of the Labour Party and Leader of the Opposition from 2014 to 2017 and a senior minister in the Labour governments led by Jacinda Ardern and Chris Hipkins from 2017 to 2023, including as Minister for Treaty of Waitangi Negotiations, Minister of Justice, Minister of Health and Minister of Defence.
From 2014 to 2017, he was the leader of the Labour Party and the opposition. From 2017 to 2023, he served as a senior minister in the Labour governments led by Jacinda Ardern and Chris Hipkins. He held various ministerial positions including those for Treaty of Waitangi Negotiations, Justice, Health, and Defence.