Prime Minister John Key says signing up to the Trans Pacific Partnership could stop the Government from banning house sales to non-residents, but alternative measures including a stamp duty or land tax could still be introduced.
Mr Key yesterday attacked Labour's "confused" stance on the TPP, saying the party no longer knew what it stood for and its caucus appeared to be split on the 12-nation agreement.
Labour announced its position last week, saying it would support the TPP only if several conditions were met, including a ban on foreign purchases of residential property.
Mr Key said that if New Zealand signed the TPP, it would not be able to ban foreigners such as American film director James Cameron from buying more property. Even if it was possible, he said, there was no appetite for it.
"I don't want to ban foreigners from buying residential property," he told TVNZ's Q+A. "I don't think that's actually good public policy that works."