He was educated on Aitutaki and Rarotonga before studying law at the University of Auckland in New Zealand and the University of Tasmania in Australia.
He is leader of the Cook Islands Party and has been since November 2010. He worked as a lawyer before entering politics. Puna first stood for Parliament at the 2004 election, contesting Robert Woonton"s seat of Manihiki.
He narrowly lost the seat on election night, but challenged the result in an election petition.
He subsequently lost his seat in the Manihiki constituency to Apii Piho in the 2006 election, but continued to serve as leader outside Parliament. Puna worked as a lawyer and pearl farmer during his time out of parliament.
In September 2009, Puna was unanimously re-elected party leader. On 30 November 2010 he was sworn in as of the Cook Islands.
Puna made his first official visit to New Zealand as in August 2011.
In September 2006, following the retirement of party leader Geoffrey Henry, Puna was elected leader of the Cook Islands Party.
Because he was not a member of Parliament, Puna was not the leader of the opposition. This position was filled by Tom Marsters. lieutenant was under Puna"s premiership that the Cook Islands became, in November 2011, a founding member of the Polynesian Leaders Group, a regional grouping intended to cooperate on a variety of issues including culture and language, education, responses to climate change, and trade and investment.