The Government is coming under pressure to relax the rules on the use of genetic engineering, with Treasury and the Ministry for Environment saying the rules are costing the country millions.

They are urging the Government to review restrictions, saying New Zealand is missing out on agricultural and environmental gains.

"If we had some change in this area New Zealand could be a powerhouse in animal genetics that would help our economy tremendously," says Warren Parker, chief executive of the Crown-owned research facility Scion, which is approved for GM field trials.

It is looking at faster growing pine trees, but under current laws, any commercial release will be difficult.

"Science is like any other business, they need the regulatory environment to be clear, at the moment it's expensive, it's unclear, and it's uncertain in terms of what the procedures are over the next decade," Dr Parker says.

Gaining public approval will be difficult, however, with fierce debate earlier this century effectively seeing New Zealand become "GM free".

Countries such as Brazil are relaxing rules, preparing to cultivate genetically modified eucalyptus trees which produce around 20 per cent more wood.

Trials have been controversial, and any such move in New Zealand will be as well.

"The Treasury is out of touch with market realities," Simon Terry from the Sustainability Council says.