"It is another racist decision, no question about that," he said on his Radio Live show this morning.
He said he would make no further comment until a press conference this afternoon.
The board had proposed the spelling be changed to Whanganui after local iwi committee Te Runanga O Tupoho petitioned for the change, a move vehemently opposed Mr Laws.
The decision will anger most residents of the riverside city -- in a referendum held in May they overwhelmingly rejected the board's proposal.
The board -- which was unanimous that the name should be changed -- said there should be 12-month transition period.
Any name change would have to be first approved by Minister for Land Information Maurice Williamson, who may confirm, modify or reject it.
The board recommended that a minimum 12-month transition period be applied. Both names could be used during the transition period.
A paper by historian Diana Beaglehole, commissioned by the Wanganui District Council, had concluded that Wanganui was the correct version.
In the paper, Ms Beaglehole found that Wanganui first began appearing in written form in the late 1830s.
Board chairman Don Grant said the board was referring the final determination to the minister because objections were received on the proposal.
If Mr Williamson confirmed Whanganui as official, government departments and local authorities that publish new/revised documents (such as maps, but also including web pages) would be expected to use the official name.
"However, for private businesses and organisations, it would only apply to publications they produce that are intended for travellers or tourists, and for geographic and scientific publications," Dr Grant said, "Businesses could choose whether to adopt the official name in their business name and their publications, or whether to retain the current spelling Wanganui.
"Even within the tourist industry, there would be no requirement to change the names of any business or company -- such as motels and guest houses." Dr Grant said the board considered all the submissions it received, and weighed up the community's views and the history and long-term usage of Wanganui.
Public submissions were relatively evenly split, with 444 opposed, and 436 in support. Nine were neutral.
Views expressed directly to the minister included 22 opposed and one in support.
"We took careful note of the Wanganui District Council submission, the referendum conducted by the council in 2009, and the research of Dr Diana Beaglehole commissioned by the council," Dr Grant said.
Other information the board considered included evidence of the use of the "h" in early historical records, and the fact that the issue of spelling was one that began from the 1840s.
"In the end we could not overlook the fact that Wanganui is not correctly spelt and it is a Maori name that is of significant cultural importance.
"Historical evidence has shown that early settlers clearly intended the name of the city to be derived from the Maori name for the river, and consistent modern usage of the language showed the spelling should be Whanganui, not Wanganui."
