Wellington  - A row erupted Monday over an official decision to put the letter "h" into the name of the New Zealand North Island city Wanganui to restore its original Maori spelling after 155 years.

The ruling came from the New Zealand Geographic Board, which is the last word on the spelling of places on the map, and follows its decision 18 years ago to change the name of the river that flows through the city of 40,000 people to Whanganui.

The board agreed with a local Maori tribe that the city was spelled incorrectly by British colonists in 1854 when they adopted the indigenous people's name for the place, a port city on the west coast, 200 kilometres north of the capital, Wellington.

City councillor Rana Waitai said the word Whanganui meant "large harbour" in Maori but Wanganui had no linguistic meaning and a name change would correct an historical inaccuracy.

But enraged city mayor Michael Laws promised to fight the spelling change which he said "is seeking to destroy our culture and heritage."

"This is a direct attack upon our city and our citizens," he said. "It will be resisted with all effort and endeavour by the Wanganui District Council and the vast majority of the citizens of Wanganui."

The council voted 8-5 against the change last month and Laws noted that 82 per cent of voters wanted the name Wanganui kept in a referendum on the issue in 2006.

He threatened to organise another referendum to stop the change which the board said remained open for consultation. (dpa)