WINNIPEG - A small group of aboriginal protesters plans to block rail traffic in Manitoba on Wednesday.

Former Roseau River chief Terry Nelson told the Aboriginal Peoples Television Network that blockades are the only way Prime Minister Stephen Harper will be forced to negotiate with aboriginal leaders.

"This isn't a round dance, this will have consequences," Nelson reportedly said. "It will block everything going east and west."

Some chiefs have declared Wednesday a national day of action. Blockades are also expected in

Saskatchewan and Ontario, including at the Ambassador Bridge - North America's busiest border crossing, which connects Windsor, Ont., and Detroit.

Chiefs from all of those provinces refused to meet with Prime Minister Stephen Harper on Friday because

Gov. Gen. David Johnston wouldn't attend the working meeting.

Perhaps no chief was more opposed to meeting with Harper without the governor general than Derek Nepinak, grand chief of the Assembly of Manitoba Chiefs. Three days after attempting to physically block other Canadian chiefs -including Assembly of First Nations Chief Shawn Atleo - from meeting with Harper, Nepinak defended the decision of Manitoba chiefs to skip the meeting. He said they collectively decided they wouldn't subject themselves to a "coercive dictation of schedules, time limits, and the Harper government agenda."

"It was determined that it is time to start standing with our people and scale back the expectations and blind trust that so many of our people have had in a federal government that only applies policy on us, not a real and true relationship based in trust and nation-to-nation respect," he said.