"They promised they would build new safe ones and not a sod of earth has been turned while demand has continued to grow," he said.
"There are very few houses for rent in Napier and certainly very few affordable houses to rent if you receive or are close to the minimum wage or are on a benefit."
People are often issued a SNG more than once.
There were 513 grants from Napier MSD service centres and 162 from Hastings.
The grants are for one week while MSD works with people to help find long-term accommodation.
The one-week limit was why dozens were squeezed out of emergency motel accommodation in February due to pre-bookings for harvest workers, Art Deco Weekend and the national kapa haka championships.
Moteliers spoken to by Hawke's Bay Today said people with poor credit records and a lack of references from a previous landlord struggled to find accommodation in the private sector.
Mr Nash said the grant figures showed "the absolute need for the government to build state houses".
A Labour government would build 1000 new houses a year for 10 years, half of those outside Auckland.
Housing New Zealand acknowledged Napier's need and no matter which party governed he would "be pushing very hard" for social housing rebuilds in Napier.
His National opponent in the coming election, David Elliott, did not respond when asked if the reason for the higher number of Napier SNGs was because demolished dwellings were not restored.
He said National was committed to helping vulnerable New Zealanders, spent about $2 billion annually on housing support and was funding up to 60 more emergency housing places in Hawke's Bay.
"This is a record investment in social and emergency accommodation, and we're taking action that no other Government has to tackle homelessness," he said.
"It's a complex issue but National is focused on addressing it. That's why we changed the SNG, which no longer has to be repaid. It simply wasn't fair to make those in need end up in further debt while they were trying to get a roof over their heads."
He said Housing New Zealand owned 1427 houses in Napier City and over the next three years MSD was looking to purchase 125.
"The biggest thing we can do to address housing vulnerability is continue to grow the region's economy, lift incomes and ensure more people can live independent lives without taxpayer support."