Labour leader David Cunliffe says a Labour-led government would demand higher environmental standards of oil companies prospecting in New Zealand.
Energy and Resources Minister Simon Bridges announced on Wednesday that the Government is opening up 405,000 square kilometres of land and sea for oil and gas prospecting - double the area it awarded last year.
The duration of the exploration permits ranges from 10 to 15 years.
Mr Cunliffe says his party is not opposed in principle to oil exploration, but would require any existing exploration permits to meet higher enviromental standards.
Areas being offered for oil and gas exploration include onshore parts of the East Coast, Taranaki and the West Coast; and offshore areas near Cape Reinga, the New Caledonia Basin and land on the East Coast, Taranaki and the West Coast.
The Green Party says Mr Bridges should resign as Associate Climate Change Minister because the portfolio is at odds with his role as the Energy and Resources Minister.
Greens co-leader Russel Norman says New Zealand needs climate leadership from Government but instead Mr Bridges is proudly supporting the industry that is the source of the problem.
Mr Bridges insists there is no conflict between his portfolios.