Clearly there are differences of income and status between and within these different working class sectors, but that’s been characteristic of all stages of working class formation under capitalism. What they have in common, however, is more important than what divides them - specifically an inherent tendency to form or join unions where the opportunity presents itself, rooted in their MATERIAL interest as hourly wage or salaried workers. The last period of labour militancy which ended in the 80’s, for example, prominently included the newly-organized sectors of the workforce (teachers, nurses, journalists, government workers, and others) produced by the rapid postwar expansion of the welfare state and service economy.
Nor is there much to distinguish these sectors ideologically, in terms of their level of consciousness. Today’s workers in all industries and at all levels, with few exceptions, are much less class conscious than preceding generations and support bourgeois parties rather than engaging in independent political action behind union-based and avowedly socialist parties as many once did
I continue to maintain anyone who works for a wage or salary may be fairly described as belonging to the working class (eve if not a class “for itself”), while the petty bourgeoisie comprises small propertyholders whose economic survival depends on profits, interest, and rent. Consequently, they frequently find themselves in conflict over measures to raise the wage level and other workplace conditions as well as public spending on social programs. Their respective interests typically steer the former to (“liberal”) left-centre parties and the latter to (“conservative”) right-centre ones.
As has been noted, the issue of class position is more complex in large and highly stratified public and private enterprises where the line between the more highly educated and well paid employees and management is often blurred. Here it’s important to note that unions have always taken the position that wage and salary earners - including many with supervisory responsibilities at all levels - should have the right to organize and bargain collectively so long as they don’t have effective control over the strategic direction of the organization. Employers have always taken the opposite view, and have sought to exclude large numbers from unions precisely on grounds they are “managers” rather than employees.
We should avoid falling into the same trap, by whatever mode of faulty reasoning takes us there.