"We've found properties from Auckland to Invercargill that are being marketed to offshore speculators.
"There is no benefit to New Zealand in selling our homes to speculators who have no intention of living here.
"That can only increase demand, and help drive up prices."
Mr Scott said the policy would make little difference.
Foreign buyers looking to make significant rural purchases would still need to go through the Overseas Investment Office consent process before buying land.
Foreign investors made up about 1 per cent of local buyers and generally moved into the area for employment, or investment in the forestry industry, he said.
"We'd love them to come here. Our margin's quite depressed."
Housing sale figures for the Wairarapa released by the Real Estate Institute of New Zealand show the number of houses sold in June 2013 dipped to 47 compared to 54 in June 2012.
However, the median property price jumped from $221,000 to $250,000 over the same period.
Prime Minister John Key said there was a limited number of foreign home buyers, and Labour's policy would have little impact on the market.
"The reality is that not that many people come in and buy properties that aren't either permanent residents or aren't going to take up personal residencies." APNZ