What is the duty of consultation in aboriginal law?

Following recognition of a duty to consult in Sparrow, Delgamuukw v. British Columbia, 1997 CanLII 302 (SCC), [1997] 3 S.C.R. 1010, developed the concept further. Lamer C.J. held that the duty to consult in the context of legislative decisions infringing upon proven claims of aboriginal title was imperative, stating at para. 168: ...There is always a duty of consultation. Whether the aboriginal group has been consulted is relevant to determining whether the infringement of aboriginal title is justified. The nature and scope of the duty of consultation will vary with the circumstances. In occasional cases, when the breach is less serious or relatively minor, it will be no more than a duty to discuss important decisions that will be taken with respect to lands held pursuant to aboriginal title.