New Zealand First is calling for a support package for businesses affected by the closure of the Manawatu Gorge highway.
The State Highway 3 route linking Hawke's Bay and Wairarapa to Manawatu and State Highway 1 was closed in April because of a large slip,
On Friday contractors fixing the highway were taken off-site because of fears a large, highly unstable area could tumble down.
An urgent upgrade to the Saddle Road detour, costing $8.5 million, will now be fast-tracked.
New Zealand First is aghast that the Manawatu Gorge has been closed "indefinitely", says leader Winston Peters.
"If this was the Auckland Harbour Bridge the government would be all over it like a rash. But because this is in provincial New Zealand it is treated like an also-ran," he said.
Mr Peters asked why the problem had not been picked up earlier, or when other slips struck in 2015, 2012, 2011 and earlier.
"What is for certain is that the Manawatu Gorge closure is like an earthquake upon businesses and their staff.
"Those near the gorge and in Woodville have hung on but now deserve help from this government because this decision is a disaster for them," Mr Peters said.
Woodville resident Bruce Hutton said residents were also frustrated at the prospect of using the slow and windy Saddle Road or Pahiatua Track routes between Hawke's Bay, Manawatu and Wairarapa.
He said tourism and small businesses would suffer as motorists become put off travelling to the region.
NZTA says a slip as large as or larger than the 2011 slip which closed the road for 14 months, could come down at any time.