Local 4-44 president Dino Chiodo says Unifor will take company size into account when deciding certain standards. (CBC)

Unifor officials are pushing for minimum standards for wages, benefits and working conditions at auto parts plants across Ontario.

The union said it's not right for there to be a patchwork of collective agreements, with compensation packages that can vary dramatically. 

Unifor said companies should pay workers equitably, and is now working on a standardized compensation template for the 4,200 unionized workers in dozens of companies in the auto parts sector.

Flavio Wolpe, the president of the Automotive Parts Manufacturing Association, won't comment on the union's approach directly, but in a phone interview from Toronto, he told CBC Windsor he wants to ensure his members remain competitive on a global scale. 

Dino Chiodo, the president of Local 444 in Windsor, said Unifor would take the differences in company size into account, and come up with different standards, depending on where the employer sits in the supply chain.

"So you would look at tier one, tier two, tier three manufacturers, and...what we believe as an organization together what that entry-level wage should be and what that competitiveness looks like in order to make sure that those companies remain pliable and competitive within manufacturing in Ontario, in Canada and with the rest of the world."

The union has a long history of using pattern bargaining when dealing with Ford, GM and Chrysler.