If New Zealand First held the balance of power after the November 26 election, deals like KiwiRail's decision to source rail wagons from China would stop, he said in an interview.
About 40 jobs will be lost from Hillside because of the Chinese contract, something that would cause great harm to the Dunedin economy.
"Hillside was forced in their bids to add in costs that guaranteed they would fail against overseas bidders. Hillside's bid was artificially inflated. The Chinese didn't have to pay ACC, a free health system or a welfare system.
"If the wagons were built here, the money would be spent here and support the Dunedin workforce, rather than being spent in another economy," Mr Peters said.
A Save Hillside Rally will be held in the Octagon on Saturday.
Mr Peters said the loss of Hillside jobs because of the Chinese contract continued the sad story of neglect since 1993, when a previous National government sold New Zealand Rail to investment bank Fay Richwhite and Wisconsin Rail.
Every last cent of profit was extracted before the government led by Helen Clark bought it back.
"This problem is the mirror image of New Zealand's problems. We need to have faith to use our own resources to add value to our economy.
"Since I heard Prime Minister John Key's unanalysed claims about 170,000 new jobs, all I have heard is about thousands of job losses - people in the heartland."
Mr Peters was in Dunedin to meet supporters and to attend a fundraising event in Dunedin South last night.
The object was to keep the party organisation growing before the annual conference, at the end of the month in Auckland.
About 90% of party officials and most of the former New Zealand First MPs had remained committed to the party since the election defeat in 2005, he said.
