OTTAWA - The federal review panel assessing the controversial Northern Gateway oilsands pipeline to B.C. is now demanding that Enbridge table a report from a U.S. regulator who concluded that the company acted like the Keystone Kops in a 2010 Michigan spill and had a corporate "culture of deviance."

The request was among a series of tough new questions the panel is putting to Enbridge on matters relating to safety, including the company's plan to deal with leaks and with unforeseen weather calamities that might endanger supertankers approaching or leaving Kitimat.

The panel, operated by the National Energy Board and the Canadian Environmental Assessment Agency, also questioned whether the company has the insurance capacity to cover the costs of a catastrophic spill.

And it asked the company to assess how less risky the pipeline will be as a result of $500 million in new safety measures announced in the wake of the devastating U.S. regulator's report.

The letter effectively reverses the panel's position on Monday, when it said it wouldn't demand that the scathing U.S. National Transportation Safety Board's findings be entered into the registry as official documents that could be considered by the panel.

Several prominent pipeline critics expressed surprise Monday that the panel wasn't pushing Enbridge to produce the NTSB interim and final reports issued last month.

They said Canada could learn lessons from the 2010 Enbridge spill that sent an estimated 840,000 gallons of diluted bitumen crude gushing into Michigan wetlands, a creek and the Kalamazoo River.

"The panel requires further information regarding this spill (in Michigan in 2010) and the subsequent actions that have been taken and will be taken to address the issues which have come to light during the investigation by the NTSB," the panel states in its 20-page list of requests.

CEAA spokeswoman Annie Roy didn't specifically explain why the panel's position changed over 24 hours, other than to note that its work is a "continuous process."

Northern Gateway critic Robyn Allan, a former Insurance Corp. of B.C. chief executive, praised the panel's new position but said it doesn't go far enough.

"This is very encouraging from the perspective of transparency and reliability at the hearings," she said in an email interview.

"What is still missing is any request for the accompanying documents to the NTSB report including both the written testimony of individual Enbridge employees and background technical studies and Enbridge's own internal report."

The panel's letter responds to critical testimony during the hearings from members of the public, including Allan and environmental groups.

Allan in particular has raised questions about whether Enbridge, which is building the pipeline through an entity called the Northern Gateway Pipelines Inc. Limited Partnership, has adequate insurance to follow through on its public commitment to "make good" on any major spills.

"The panel requires elaboration on the 'make good' statement," the letter states, asking whether there are any financial limits on the commitment.

There are numerous other demands being put to Enbridge:

The company is asked if it still takes the position that it is "not possible to predict the financial cost of a spill."