In a Feb. 3 letter, panel Chairman Robert Hornal delivered a stern rebuke, suggesting the proponent may not “fully appreciate the level of detail” required before the environmental phase can move to full public hearings.

He said a deadline of Feb. 18 for responses will be extended to March 31.

“Until sufficient information is filed by the proponent in response to this letter, the panel will not be in a position to schedule further rounds of IRs (information requests), or set the matter down for hearings,” Hornal said.

The new deadlines put a cloud over hopes that hearings might begin in April.

A spokesman for Imperial Oil, the lead partner in the Mackenzie consortium, told reporters the responses will be delivered as quickly as possible.

Although that job is well under way, he noted that more than 600 requests for information have been received by the panel.

In recent weeks, the panel has been deluged with criticism of the applications filed last October and calls for a postponement of the current regulatory round from environmental groups, such as the Canadian Arctic Resources Committee, Sierra Club of Canada, World Wildlife Fund and Canadian Parks and Wilderness Society, plus communities along the pipeline route and aboriginal organizations.

Hornal said the 6,500-page initial application failed to properly address the impact on communities and the environment and how the consortium planned to minimize any harm.

“The information required from the proponent to address these gaps is substantial in scope and detail,” he said in the latter.

Hornal said there “may be a divergence” between the consortium’s “understanding of impact assessment review by a panel and the panel’s expectations.”

Although the panel can neither approve nor reject the pipeline, its findings will carry weight with the National Energy Board and the Canadian government.