Labour leader David Cunliffe has reiterated the party's stance on deep sea oil drilling and exploration, saying it is not opposed to it in principle.
However, he says a Labour government would change the law to ensure that all permits meet world best standards.
Mr Cunliffe said on Wednesday a Labour government would not prohibit deep sea drilling, as proposed by the Greens.
"There will be no opposition in principle to deep sea oil exploration, but there will be world best practice on environment standards including full liability cover. If new consents can't meet world best practice they will not proceed."
Labour is considering a model similar to Norway, where the government receives royalties from the proceeds of drilling operations, he says, but no decisions have been made.
Prime Minister John Key says the party's stance just demonstrates problems it would have if it tries to form a government with the Greens after this year's election.
The Greens have called for a prohibition on all exploratory deep sea drilling. Mr Key says that just shows how far apart the parties are on some issues.