Labour's foreign investment policy is being criticised by political opponents as smoke and mirrors, without offering anything new.
At Labour's annual conference over the weekend, leader Phill Goff said the party would effectively end the sale of farmland to overseas investors and restrict foreign ownership of strategic infrastructure if it becomes the government.
Under the policy, foreign investors couldn't own more than 25% of the country's airports, sea ports, electricity line companies, roads or railways.
Prime Minister John Key says that's illogical, because it would force local companies such as Infratil to review their international shareholdings.
Also, Mr Key says, companies with offshore shareholders would find it difficult to borrow on international debt markets because lenders wouldn't have security over their assets.
Mr Key says Labour has not thought through the policy.
Finance Minister Bill English says the recent changes to overseas investment rules already make it easier for the Government to reject sales of large tracts of farmland.