A ruling class does not necessarily have to be an oligarchy, it need not formally monopolise political power to effectively rule. Political pluralism is quite compatible with capitalism because the capitalist class rules economically. The capitalist ruling class's real basis of power is their control over the means of production, they rule over the economy.
Political governments come and go and no matter their persuasion or sympathies, their real power is extremely limited. Pro-labour governments have little room to manoeuvre within this capitalist landscape.
Bill Bartlett Bracknell Tas