RCMP members are before the Supreme Court of Canada making a final pitch for their right to form an independent union.
They are appealing an Ontario Court of Appeal decision which found that federal labour laws which exclude RCMP members from collective bargaining do not violate the Charter of Rights.
RCMP regulations provide for elected staff-relations representatives who are to be consulted on staff and pay issues.
The Mounted Police Professional Association of Canada says that's not good enough and has been fighting for the right to collective bargaining.
The association won a victory in the Ontario Superior Court of Justice in 2009, but that was overturned on appeal in 2012.
There are about 18,000 uniformed Mounties in the national force.
The association argues that denying them the right to unionize threatens collective bargaining rights generally.
Some major labour bodies, including the Canadian Labour Congress and the Public Service Alliance of Canada, are interveners in the case.
Rae Banwarie, the association's president, said the challenge could prove to be a landmark case, especially if the court sides with the RCMP and the staff relations representatives system.
"It will be the beginning of the end for collective bargaining in Canada, as employers could justifiably impose labour programs and deny employees the right to select independent associations to bargain on their behalf," he said.
"Canadians deserve better. This unchecked power is not acceptable in a just and democratic society."
Lawyers for the Attorney General of Canada argued at the appeal court that the staff representative system more than meets constitutional scrutiny.
They said the reps are elected to provide fair and equitable representation to management and to participate in developing policy and procedures that affect employment.