Labour leader David Shearer wants a law change so governments have to throw out any foreign bid to buy New Zealand farms, unless the offer would result in more jobs and more exports than any New Zealand bid could.
The proposal, Mr Shearer's first significant policy move as leader, would result in most applications from foreigners to buy sensitive land in New Zealand being turned down.
The door would be open only to new technologies and new products.
"We don't want foreign corporates buying our land and seeing the value flow out of New Zealand," he said.
Mr Shearer's member's bill, released yesterday, would restrict the way ministers approve of Overseas Investment Office decisions.
It comes as the fate of the Crafar farms remains up in the air. The Government had approved a bid from China company Shanghai Pengxin, but this was overturned in the High Court, which found that potential benefits had to be measured against an alternative buyer.
At present two Government ministers have to approve any OIO decision. They consider several factors and can decide which factors are relevant and to what degree.
Mr Shearer's bill would replace this with a stricter test. If the applicant cannot demonstrate benefits through "the creation of a substantial number of additional jobs in New Zealand" or "a substantial increase in exports from new technology or new products", then ministers would have to turn it down.
To codify the High Court judgment, the bill also says any benefits would have to be additional to what would be likely with a Kiwi buyer.
This effectively means the Shanghai Pengxin bid would have failed, because of the comparable bid by a Sir Michael Fay-backed NZ consortium.
The bill has to be drawn in the members' bill ballot before it can be considered. But the Green, New Zealand First and Maori parties expressed support last night.
United Future's Peter Dunne said there was no point in commenting unless the bill was drawn in the ballot.
Labour's finance spokesman, David Parker, said most applications under Labour's bill would fail.
"They would need to bring some new process or product for us to be interested ...
"If someone turns up with some unique intellectual property that we can't otherwise access, then we'd be silly not to leave that door open."
A spokesman for Finance Minister Bill English said the proposal was confusing. "Labour wants ... to be able to turn down applications on pure political grounds."
* Government ministers must approve Overseas Investment Office approvals of foreign bids to buy sensitive land
* A bid has to show substantial and identifiable benefits. Ministers consider dozens of factors including job opportunities, an increase in exports and heritage protection and decide what is relevant and to what degree.
* Labour's bill would introduce a stricter test - the bid must substantially increase jobs or exports through new technology or new products, and these must be additional to what would happen if a New Zealander bought the land.