A workers' party must challenge and continually demonstrate the utter falsity and perniciousness of this idea. It must be continually demonstrated that the interests of the employers and the workers are diametrically opposed to each other, that the evolution of capitalist society demonstrates the existence of the class struggle rather than identity of class interests.
By accepting the identity of interests between employers and workers, the latter are forced into a subordinate position. The theory of the identity of interests inculcates in the workers the idea that the employers get their share, namely profits, and the workers get theirs, wages. Both supposedly get the fruits of their contribution to the product.
This is wholly erroneous. In reality the workers are subjected to exploitation while the employers reap the benefits of the unpaid labor of the workers. The difference between the class approach to the problem and even the most progressive trade union approach is that the latter would not acknowledge the objective significance of the relations between the employers and the workers.