Ottawa had ignored pleas begun June 4 by elders of the Five Nations for a province-wide exemption from the harmonized sales tax, scheduled to take effect July 1, The Globe and Mail reported Wednesday.
Ontario natives have not had to pay any sales tax when making purchases in the province.
An 11th-hour agreement seemed imminent after tribal leaders announced there would be major disruptions including blockades, the newspaper said.
"It's direct action that usually gets the most attention," Alvin Fiddler, senior policy adviser at the Independent First Nations Alliance, said.
An accord is close between the Five Nations and the Stephen Harper government, Stan Beardy, Grand Chief of the Nishnawbe Aski Nation, said.
"If the thing isn't resolved, we have to tell our people to do whatever we need to do in order to protect our rights," he said. "We have to shut down the country if we have to."