An over-valued New Zealand dollar is responsible for the loss of even more jobs, Labour says.

Resins maker Nuplex Industries announced on Monday it will close three manufacturing sites in New Zealand and Australia during the next two years with the loss of 80 jobs.

Labour's finance spokesman David Parker says jobs are being lost all over New Zealand as the high dollar makes products too expensive on international markets.

"Nuplex's chief executive Emery Severin put the blame on our high dollar and predicts more manufacturing will move to other countries," Mr Parker said.

"I agree - they will go to those countries that better help exporters compete."

Nuplex also blamed the strength of the Australian dollar for its decision.

Labour, NZ First and the Greens say the government must change monetary policy so the Reserve Bank of New Zealand can intervene to bring down the dollar's value.

The New Zealand dollar traded at 82.88 US cents just before 8am, little changed from 82.78 cents at the close of trading in New York on Friday.

"The workers at Nuplex who lost their jobs today can point their finger straight at the high dollar," Mr Parker said.

"It doesn't have to be like this. Action can be taken to help our manufacturers and exporters compete and keep these jobs for kiwis."

Within the last few weeks Solid Energy's coal mines and the Tiwai Point aluminium smelter have signalled job losses.

The government has rejected opposition calls for intervention, saying bringing the dollar down would make imports more expensive and reduce the standard of living.