Theresa May's government poses a challenge to us Marxists.

What I mean is that Marx and Engels saw the state as a means of promoting capitalists' interests. It is, said Engels, "the instrument for exploiting wage-labour by capital".

However, this government seems not to be acting in capital's interests. Its desire for tougher immigration controls is opposed by both the CBI and British Chambers of Commerce; even the FT calls the government "jackbooted overlords". And the pursuit of a hard Brexit is generating uncertainty and jeopardizing the City's future business.

Given this, how can we Marxists claim - as the Communist Manifesto did - that "the executive of the modern state is but a committee for managing the common affairs of the whole bourgeoisie"?

There are two answers here.

First, we should distinguish between the policies of any particular government and the basic structure of the state. It's plausible that the latter serves capitalists' interests. For example, intellectual property laws protect monopoly power; banks get an implicit subsidy because of the prospect of being bailed out in bad times; government procurement and the Private Finance Initiative serve as forms of corporate welfare*; schools act as ideological state apparatuses indoctrinating students to act in capital's interests; and the welfare state helps reduce business uncertainty whilst work assessment schemes ensure a high supply of labour. And so on.

Secondly, the state doesn't always slavishly follow the requirements of capital. Engels went on to say:

Exceptional periods, however, occur when the warring classes are so nearly equal in forces that the state power, as apparent mediator, acquires for the moment a certain independence in relation to both.

This inspired Ralph Miliband's theory of the relative autonomy of the state:

[State] power has often been used for purposes and policies which were not only pursued without reference to the capitalist class, but also at times against the wishes of many parts of that class, or even the whole of it...The state does not, normally and of its own volition, intervene in class struggle on the side of labour. But this does not mean that it is necessarily subservient to the purposes and strategies of capital. It is in fact often compelled, by virtue of its concern for the defence and stability of the social order, to seek some intermediate position, and to act upon it, however much that position may differ from the position of capital. (Divided Societies, p 31-32).

This is what we're seeing now. Capital is relatively weak which has given the state an unusual degree of autonomy. Capitalism's failure to deliver rising living standards (a process exacerbated by Osborne's austerity) has generated a nationalist backlash which May feels compelled to accommodate even at a cost to business.

In this sense, May's policies aren't a refutation of a Marxian theory of the state after all.

But this poses a question. Mightn't the notion of relative autonomy serve as what Popper called an "immunizing strategy" - a way of protecting Marx's theory of the state from any possible refutation? If so, what would refute that theory?

Simple. If the state were to maximize labour's bargaining power at the expense of capital - for example via a high citizens income, jobs guarantee and promotion of worker coops - it would cease to be "a committee for managing the common affairs of the whole bourgeoisie". Until this happens, however, Marx's theory of the state looks reasonably valid.

* Yes, estimates of the size of the corporate welfare state are flawed, but this doesn't change the fact that big government does help capitalists, which is why so few capitalists are libertarians.