While some Indigenous activists gear up to fight expansion of the Kinder Morgan Trans Mountain pipeline on the streets and in court, federal Liberal cabinet ministers say there's no going back on their decision to approve the $7.4-billion project.

Inspired by some of the tactics used by protesters at Standing Rock in North Dakota, the Secwepemc Nation, situated along the Trans Mountain route, said Wednesday it was preparing to build "10 tiny houses" in the path of the project's construction as a protest and with the hope of forcing a delay.

"The house is a symbol of the community's opposition to the pipeline and a message to the Trudeau government that the pipeline does not have Secwepemc consent, a right protected under the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP)."

Speaking to reporters at the national Liberal caucus meeting in Kelowna, B.C., Indigenous Services Minister Jane Philpott said such groups are free to stand in opposition, but the decision to approve is final.

"We know there are a variety of different views on this," Philpott said. "But this is something we've already done a tremendous [amount] of work on, recognizing the principles of consent, recognizing the rights of First Nations."

Carolyn Bennett (left), minister of Crown-Indigenous relations and northern affairs and Indigenous Services Minister Jane Philpott take questions from media. (Sean Kilpatrick/Canadian Press)

Trans Mountain announced Wednesday it has finalized agreements with six contractors to build portions of the 1,150-kilometre expansion project that will carry crude oil from a terminal near Edmonton to Burnaby, B.C., something the company calls a "major milestone." Construction is set to begin later this month.

Federal cabinet approved the project last November. Prime Minister Justin Trudeau said the infrastructure is needed because of a dearth of pipeline capacity for Alberta producers. At the time, Trudeau said the government expects Kinder Morgan to "meet and exceed" the 157 conditions the National Energy Board imposed on the project, including spill-mitigation plans.

Environmentalists and their First Nations allies are planning a march Saturday titled "Kinder Morgan, We Still Say No!" in an effort to keep pipeline opposition on the agenda.

"Despite widespread opposition, Kinder Morgan is still promising to start construction of the Trans Mountain pipeline expansion in first part of September. We don't know exactly what Kinder Morgan is planning, but we do know we need to be united and mobilized to stop the pipeline," the group said in a Facebook post.

Call for calm

Natural Resources Minister Jim Carr said he expects to hear from some jittery B.C. MPs worried about the start of construction and the protests that will soon follow.

"We have a caucus of 184 very talented men and women, and the shyness gene is not dominant in MPs, and it's their role to express the views of the people who elected them, and that's what happens in caucus meetings," he said.

Randeep Sarai, the B.C. Liberal caucus chair, said he is calling for calm ahead of the construction start date.

"I ask that those who have opposition to go, in accordance with the law, and some of them have put their grievances in the court, and work according to that legal process. We're definitely open to hearing what the courts have to say, but currently the project is approved," he said in an interview with CBC News.

The B.C. NDP government recently won approval to act as an intervener in a Federal Court of Appeal case launched by some First Nations along the pipeline's route, casting some doubt on the future of the project.

B.C. Premier John Horgan has vowed to do all that he can to stop construction, but Carr brushed aside those threats.

"The message [to Horgan] is that this is a federally approved pipeline that we believe is in the national interest. Those are the reasons we took the decision in the first place, and nothing that's happened since then has changed our mind that this is a good decision for Canada.

"The decision was made with all of the facts, with all the scientific evidence, with all of the input, and we believe we made it for the right reasons and we stand by the decision."

The Federal Court of Appeal hearings on the Trans Mountain pipeline will be held in Vancouver and are set to run Oct. 2-13.