Tonga's prime minister and democracy campaigner 'Akilisi Pohiva has died at the age of 78, after being rushed to a New Zealand hospital on Wednesday.

Mr Pohiva suffered from ill health in recent years and was flown from the Tongan capital Nuku'alofa but died on Thursday morning in Auckland's City Hospital.

A “commoner” who regularly clashed with the Tongan royal family and nobility, he rose from being a school teacher and lecturer at Tonga Teacher's Training College to lead his country.

Stefan Armbruster/SBS News

Elected to parliament in 1987, in 2014 he became the first “commoner” to be elected prime minister, by parliament rather than appointed by the King, and was returned to office in 2017.

At last month's Pacific Island Forum leaders' meeting, despite being in very poor health, Mr Pohiva argued strongly for action on climate change and was moved to tears over the testimony of children affected.

He also took a strident stand on self-determination for West Papua.

***MESSAGE OF CONDOLENCE ***



It is with a heavy heart that the Brisbane Tongan Community mourns the passing of the Prime Minister of the Kingdom of Tonga, Hon. Samuela 'Akilisi Põhiva in Auckland, New Zealand aged 78.



Part 1 pic.twitter.com/kJ0iKx38ES — Brisbane Tongan Community (@BrisbaneTongan) September 11, 2019

My condolences for a good friend and principled leader. RIP

Tongan PM 'Akilisi Pohiva dies, aged 78 https://t.co/FZVQ9WsnkG — Ralph Regenvanu (@RRegenvanu) September 12, 2019

His life included many clashes with the Crown in the fiercely monarchical state, arguing for a relinquishing of powers from the King.

That came in 2008, when King George Tupou V gave over many responsibilities to the parliament and the government, clearing the way for Mr Pohiva's eventual prime ministership.

AFP

Active since the 1970s as a human rights and pro-democracy campaigner, his commentaries in Tongan media drew the ire of the royal family and resulted in his dismissal from the public service in 1984, which he successfully challenged in court.

In 1996 he was imprisoned for contempt over his coverage of parliament, which the Supreme Court overturned as “unlawful and unconstitutional”, and was charged with sedition in 2002 for reporting on the royal family’s financial interests, for which he was found “not guilty” by a High Court jury.

Tongan authorities are yet to make public statements on Mr Pohiva's death, but Tonga’s parliament has gone into recess as a mark of respect.

Condolences have also been offered from around the Pacific region.

"As one of the longest serving parliamentarians in our region, Prime Minister Pōhiva dedicated his life to the service and leadership of his country and people," said Pacific Islands Forum secretary general Dame Meg Taylor.

"During his political career we saw him transition from firebrand activist to an elder statesman of the Blue Pacific always staying true to his strong ideals of democracy and human rights.

"I will remember him as a fighter until the very end. May his legacy stand true and be an inspiration to the people across the Blue Pacific."