Union workers representing the Big Three US carmakers as well as suppliers are pushing for the end of the two-tier wage system.

The rank-and-file members are publicly voicing their opposition to the lower wage since the UAW began negotiating new labour contracts with Chrysler, Ford and General Motors last month.

Mark Harris, a worker at a parts plant formerly owned by Ford, said: “There shouldn't be a tier one or a tier two or a tier three, four or five. There should just be one wage. A UAW wage."

The second-tier wage was established in 2007 to help the auto makers deal with diminishing profits and compete against the foreign counterparts operating in the US. It allows new hires to be paid US$14 an hour while veterans can make up to $35.

A weekend meeting of union workers heard that second-tier earners were treated badly on the production line by their higher-paid colleagues and there was concern over trying to make ends meet on the lower wage.

Some said they struggle to pay their own mortgages while others said they can't afford to buy the cars they make.

They now plan to rally a grassroots effort to vote down the contracts unless the two-tier wage system is abolished.

The UAW has said it will not comment on negotiations.