The Manufacturing Workers Union is concerned that the real impact of cuts to blue collar workers at the Mitsubishi plants in Adelaide has been understated.

Last month, the car maker announced it would cut 600 positions in an effort to bring its Adelaide plants to the break-even point, saying most of the jobs would be in clerical and managerial areas.

However, union state president Ian Curry says up to 200 of the job cuts could be classed as "blue collar".

He says workers have been meeting this week to discuss a log of claims over the redundancies.