B.C.’s New Democrats have formally registered opposition to Enbridge's controversial proposal to build a pipeline from the Alberta oilsands to the port of Kitimat in northern B.C., arguing the risks outweigh the benefits.

Official Opposition leader Adrian Dix and 35 MLAs signed the 11-page letter sent on Monday to the National Energy Board's joint review panel, which is tasked with assessing the Northern Gateway project.

"Under the Enbridge proposal, British Columbia would assume almost all the project's risk, yet would see only a fraction of the benefits," said Dix in a release. "By any measure, such a high-risk, low-return approach simply isn't in B.C.'s interests."

In January, a three-member panel began public hearings to assess the environmental effects of the $5.5-billion plan to transport crude through a 1,177-kilometre twin pipeline for collection by huge oil tankers that will ship it to Asia and the United States.

A host of groups have already voiced concerns over the massive undertaking, complete with a variety of protest rallies.

That includes a declaration signed by more than 60 B.C. First Nations and aboriginal organizations, and more opposition from at least B.C. three cities and a regional district. The Union of B.C. Municipalities has also passed a motion against the project.

The governing B.C. Liberals have said they're waiting for the panel's report before taking a stand.

Within the letter, the NDP lists six key concerns that prompted its conclusion.

B.C. 'has not used its full powers'

It says that lifting the current oil tanker moratorium will put B.C.'s coastline in jeopardy, could create danger for habitats in the nearly 800 streams it must cross and would severely affect First Nations communities if a spill occurred.

It also says oilsands-related development would generate greenhouse gas emissions that will contribute to climate change, provides few long-term or sustainable economic benefits and would likely increase oil prices for Canadian consumers.

"While we acknowledge the role of the federal government in regulating interprovincial pipelines and marine transportation, we strongly emphasize the responsibility of the provincial government both to represent and to protect the interests of British Columbia and British Columbians at every opportunity," says the letter.

"We are very concerned that the province has not used its full powers to do this."

Enbridge has said the project will generate jobs while being built and operated safely.

Four NDP MLAs are participating in the joint review panel process, which is expected to hand a recommendation over to the federal Conservative government in late 2013.

If the process wraps on schedule, it will come in just under 24 months. More than 4,300 individuals and groups have registered to speak at the hearings across B.C. and Alberta.