The government has decided to bring home a group of New Zealand SAS troops currently in Tonga for a training exercise.

Photo: RNZ / Alexander Robertson

Tongans will head to the polls in November after the King's sudden decision to dissolve parliament, effectively sacking the Prime Minister 'Akilisi Pohiva.

His government has been marred by controversy and allegations of incompetence, but he survived a motion of no confidence last year.

Foreign Affairs Minister Gerry Brownlee said having New Zealand troops there on a military training exercise could be perceived the wrong way.

"While an election is going on and parties, both current government and then opposition will be competing for the votes of Tongans - we just think it's better just to be out of it and to let the Tongan system and the Tongan people just get on with the democratic process."

Mr Brownlee said the decision to dissolve a democratically-elected parliament was a significant event and New Zealand officials were monitoring the situation closely.

Photo: RNZ Pacific/ Indira Stewart

Meanwhile, a Tongan academic and former parliamentarian Sitiveni Halapua said the King's decision was a great disappointment.

He said despite Tonga's amble towards democracy, the monarchy still had a vast amount of power.

Dr Halapua, who was part of the consultation process for the constitution which was brought in 2008, said the dissolution was likely to re-ignite Tonga's democracy debate.

He said the government had to wear some of the blame, as people had seen little change in their living situations as a result of reform.