The Athabasca Chipewyan First Nation asked the federal-provincial joint panel reviewing the project to halt the hearings while it files a constitutional challenge with the Alberta Court of Appeal.
Last week, the board ruled it didn't have jurisdiction on questions of constitutional law.
Band lawyer Eamon Murphy said Monday that the exclusion of a ruling on treaty rights call into question any decision made by the panel.
The Alberta government and Shell Canada (TSX:SHC) argued halting the hearing would lead to unfair and lengthy delays.
The panel will rule on the First Nation's motion to adjourn on Tuesday.
Murphy said if the Appeal Court overturns the panel's decision to not rule on the First Nation's constitutional argument, it would "call into question the panel's findings."
"And frankly, it's not in the public interest to have that kind of hearing take place, where decisions may be overturned."
Murphy said the constitutional argument is relevant because "the panel will be making decisions here which will potentially affect Athabasca Chipewyan First Nation's constitutionally guaranteed rights."
The band says Shell's proposal would disturb 12,719 hectares of land and destroy 21 kilometres of the Muskeg River, which is considered culturally significant.
The hearings on the project, which would increase Shell's bitumen production by 100,000 barrels a day, come five years after the company originally started the regulatory process.
(CFVR, The Canadian Press)
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