The Canadian Auto Workers union says negotiations with the Detroit Three auto makers toward a new 4-year contract have met “unprecedented demands” from the corporations, raising anxiety over a potential work stoppage with the bargaining deadline just a week away.

“The demands facing the CAW have not relented, with all three companies calling for dramatic changes to the contract,” the labor group says in a leaflet distributed today to its membership.

“The union recognizes the fragility of the industry and the need to stabilize fixed costs, while finding a solution that rewards members’ work. Unfortunately, our efforts have not been met with equal willingness by the companies to negotiate fair terms.”

The CAW earlier called for members working at Chrysler, Ford and General Motors assembly plants to prepare to strike if the two sides did not reach a new contract by Sept. 17, when the existing agreement expires.

The leaflet obtained by WardsAuto claims the Detroit Three want to eliminate pension guarantees after 30 years of service and create a 2-tier wage where new hires earn less than current employees, a salary structure that would duplicate United Auto Workers union pay scales in the U.S.

The CAW says the auto makers also want to shift employee retirement savings to defined-contribution plans, permanently eliminate cost-of-living adjustments and reduce other benefits.

“The corporations are also refusing to commit to any new investments, which puts members’ jobs in jeopardy,” the CAW says. “Each company has also insisted that any reward or bonus will be paid for by additional cuts to other areas of the agreement.

“Anxiety levels are understandably high and rising,” the union says.

The CAW broke with its longstanding policy in this round of contract talks by bargaining with all three auto makers at the same time. Historically, the union would craft an agreement with one company and then use it as a pattern for the other two.

CAW President Ken Lewnza told WardsAuto ahead of the talks he wanted the Detroit Three to compensate his members for the wage and benefit sacrifices they made during recession to keep the industry afloat.

The auto makers say they need concessions from the CAW to keep operating in the region, because a strong Canadian dollar makes it the most-expensive place to builds vehicles.