Opponents of Enbridge's controversial Northern Gateway pipeline are pointing to a scathing report into a spill in the United States to bolster their argument that the company's proposal to transport oil over remote areas of British Columbia is too risky.

The U.S. National Transportation Safety Board issued a report Tuesday into a July 2010 spill that saw more than three million litres of crude oil spill into Michigan's Kalamazoo River and nearby wetlands. The board concluded Enbridge failed to fix a defect discovered five years earlier and then responded poorly when the spill occurred.

The Calgary-based energy company is currently seeking approval for a 1,170-kilometre pipeline between Alberta and the B.C. coast -- a proposal that has drawn the ire of First Nations groups, environmentalists and the province's Opposition New Democrats.

NDP Leader Adrian Dix was quick to hold up the U.S. report as proof Enbridge's Northern Gateway project should be rejected.

Dix called on Liberal Premier Christy Clark, whose government has so far refused to take a position on the pipeline, to finally join him in condemning the project.

"The long-term effects for the people of Michigan of what happened in the Kalamazoo River will be felt for a long time and have been serious in terms of health, in terms of the environment, in terms of the economy," Dix told reporters in Vancouver.

"Here in British Columbia, those risks to our economy, to our environment have to be part of the process, and they haven't been."

The Northern Gateway project is currently before the National Energy Board, which has been holding hearings throughout Alberta and British Columbia. The hearings are expected to wrap up early next year.

The Alberta and federal governments both support the pipeline, but the B.C. government has insisted on staying neutral. The province's premier and environment minister have suggested it would be irresponsible to take a position before all the evidence is in.

But Dix said the government has failed to even provide the panel with its own evidence about the potential risks of the pipeline and of the increased tanker traffic it will spur.

"You lay out what those risks are, you provide that evidence to the panel so the panel can consider those risks," said Dix. "That doesn't involve making a decision. That involves laying out what the evidence is."

Dix said if his party wins next May's provincial election, an NDP government would do whatever it could to block the pipeline. He said that would include opposing the project in front of the National Energy Board and exploring potential legal options.

B.C.'s environment minister Terry Lake said the report into the Michigan spill was "pretty damning," but he appeared willing to give the company the benefit of the doubt.

"When you read about the culture at Enbridge, that's worrisome," Lake said in an interview.

"But again, we need to fully understand this. This happened two years ago. What changes have occurred at that company to ensure that this kind of reaction doesn't occur in the future? ... I view this as more information to help us formulate a position."

Lake defended the Liberal government's reluctance to take a position on the pipeline. He said the province still has the right to make arguments and present evidence to the National Energy Board once it feels it has enough information to come down on one side or the other.

"We've always said that we want to base our position on information, and that information is based on a cost-benefit ratio," said Lake.

"The process is ongoing, and we have not lost our opportunity (to take a position)."

Art Sterritt of Coastal First Nations, a coalition of First Nations that oppose the B.C. pipeline, said the report into the Michigan spill confirms his group's fears.

Sterritt said the report should be a wake-up call to the provincial government to oppose the pipeline.

"The reality is that the studies that we've done over the years have shown us that this is the way this industry operates," said Sterritt.

"I think the provincial government has to wake up. If she (Premier Christy Clark) doesn't wake up on this, then she's done. British Columbians aren't going to tolerate this kind of incompetence."