Legislation allowing developers to bypass local authorities and go direct to the Environment Court with consent applications for "medium sized" projects was introduced to Parliament this week.

The Resource Management Reform Bill, part of the Government's shake up of the Resource Management Act (RMA) also emphasises economic development over environmental protection, the Opposition has warned.

The bill, which will receive its first reading next week requires local authorities to agree that consents applications for "medium-sized projects" to be referred directly to the Environment Court if the project meets a particular "investment threshold".

Governments will be able to set that threshold - which has not yet been established - without parliamentary scrutiny through regulation.

Environment Minister Amy Adams was yesterday unable to give any indication of what that threshold would be but it would be set following public consultation.

Labour's environment spokesman Grant Robertson said the change "takes power from local communities and puts it directly in the hands of Ministers".

The bill also requires local authorities to place greater emphasis on assessing the costs and benefits of proposed plans which Mr Robertson said was part of a "worrying emphasis on economic development over environmental protection".

"The heart of the RMA is the emphasis on sustainable development. Singling out economic development will destroy the balance inherent in the Act."

But Ms Adams said the changes were about "asking local authorities to be clear that they understand the implications on growth and jobs in making their decisions".

"It doesn't change their discretion to make their decisions."

The legislation will also give effect to the Government's previously signalled intention to oversee appointments to the hearings panel for Auckland's unitary plan.

Critics have warned that will give central government too much power over the fast-tracking of Auckland's planning process.

Mr Robertson warned the bill also restricted council's ability to protect trees in urban areas by forcing them to identify individual trees or groves for protection under their plans rather than via wider measures.

"The result of that will be a bureaucratic nightmare that could lead to inadequate policies to protect and promote urban trees."

By Adam Bennett Email Adam