SARNIA, Ont. -- Members of a southwestern Ontario First Nation stepped up a protest in Sarnia, marching through the streets on the fourth day of their blockade of a CN Rail line in the city.

The Aamjiwnaang First Nation said both the demonstration that began at Sarnia city hall on Monday and the ongoing blockade are part of the national Idle No More protests against the Harper government's recently passed omnibus budget legislation, Bill C45.

Organizer Vanessa Gray said the rally aimed to bring the community together "to stand up for what your rights are and what you believe in."

Gray told protesters the government's legislation, which critics say weakens environmental protection, affects not only First Nations people, but "every person across the nation."

Greg Plain, who took part in the march, agrees all Canadians need to be aware of what First Nations are doing.

"It's not an Indian thing," he said. "We may be about the loudest but as far as Canadians, you all need to be advised, you know, these things are affecting all of us."

Meanwhile, there was no indication Monday of when the rail blockade would come to an end.

A court injunction has been issued giving police the power to end the blockade, but Sarnia's mayor has said they won't interfere as long as the situation remains peaceful.

Demonstrators say the blockade will continue until Prime Minister Stephen Harper meets with Attiwapiskat Chief Theresa Spence, who's on a hunger strike to bring attention to aboriginal issues.

Spence started the strike on Dec. 11, and has been living in a teepee on an island in the Ottawa River that many aboriginals consider to be sacred land.

She is seeking a meeting with Harper, the governor general and First Nations leaders to discuss the treaty relationship.

On Monday, Conservative Senator Patrick Brazeau, who is Algonquin, was rebuffed in an attempt to meet with her.

Last week, Brazeau told the Aboriginal Peoples Television Network he didn't think Spence was setting a good example for aboriginal youth.

Brazeau posted an account on Twitter of his efforts to meet Spence on Monday, saying he was first told she needed time to prepare to see him but then that she wouldn't see him at all.

"Not sure if Chief Spence's advisors made the recommendation not to meet but regardless, I respect her decision," Brazeau wrote.

Union leaders called Monday for provincial premiers to get involved in efforts to get the prime minister to sit down with Spence.

"No one level of government is solely responsible for the poor living conditions on First Nations reserves," said Paul Moist, president of the Canadian Union of Public Employees, in a statement.

"And therefore it is in the interest of the premiers to help find a peaceful and safe resolution to this standoff."