National Party leader Simon Bridges says more than 17,000 lifestyle blocks in Hawke's Bay could be affected by a proposed capital gains tax.
But Finance Minister Grant Robertson says no final decision have been made on the Tax Working Group's recommendations.
While the Tax Working Group has recommended an exemption to the family home when it comes to a capital gains tax, lifestyle blocks over 4500 square metres would not be exempt.
"The reality is, that's a little over half a rugby field," Bridges said. "There are 17,657 properties in Hawke's Bay alone which fit into that category.
"That figure doesn't include those who run a business from home, or who have flatmates."