Canadian authorities are considering proposals by pipeline company Enbridge to build its Northern Gateway project to the west coast and Kinder Morgan's expansion to an existing line despite growing opposition from coastal communities.
Elizabeth Edinger, a constitutional law professor at the University of British Columbia, told The Vancouver Sun newspaper the battle over the pipelines could find its way to the courts.
"But I can't predict the outcome at this point," she said. "But there will certainly be a serious attempt to delay (the projects)."
Canadian legislation gives Prime Minister Stephen Harper final say over energy projects considered to be in the national interest, she added.
British Columbia's New Democrat Party issued a formal objection to the Northern Gateway project in a letter to Canada's National Energy Board. The party said the planned oil pipeline poses an environmental threat to aboriginal Canadians along the western coast.
Kennedy Stewart, a lawmaker from the New Democrat Party, said that while aboriginal groups don't have the legal means to reject the pipelines, "they do have the legal tools to slow them down quite a bit."