It will be no surprise to anyone who is looking for work that you can now be sanctioned for refusing a zero-hours contract. You can be sanctioned for almost anything: failing to turn up for an appointment you didn't know about; being unable to attend a work programme placement because the fare was a third of your jobseeker's allowance.

Asked about the rise in their usage, 83% of food banks cite these sanctions as causing the delay or withdrawal of benefits. It is plain that, by means up-front and underhand, unemployment benefit is being systematically destroyed as a reliable source of income. This protective role of the state, to make sure we don't starve, has been outsourced to charities. Without it, one wonders what the state is for – which, I imagine, was the point of vandalising it in the first place. This is something to bear in mind if you succumb to the despairing thought that all politicians are the same. They are often dispiritingly similar, but we've never had it so bad.

The zero-hours contracts – of which there are now 1.4 million in the active workforce – remain a flashpoint, even if they are by no means the most unjust requirement made by the Department for Work and Pensions (they are not as bad as mandatory work activity, for instance). The statement from the employment minister, Esther McVey, that jobcentre "coaches" would be able to "mandate to zero-hours contracts" marks an important point, the moment at which the government demonstrably chose the interests of the employer over those of the employee.

Defenders of the free market insist that, since everybody now uses them, the salient point is not the zero-hours contract itself but how the employer behaves within it. The Gourmet Burger Company uses them but has pensions and paid holiday, rights that are, arguably, what the zero-hours contract was invented to wriggle out of.

That's not the norm, however. I've heard of a major fast food chain that kept employees underemployed – taking on more staff rather than give any one member more than 30 hours – while at the same time enforcing exclusivity clauses that prevented workers from taking on even voluntary work in their spare time. Workers were marched to the cashpoint if their tills were ever out. In the Costa Coffee in Channon retail park near Eastleigh, Hampshire, there was an advert for a job of about 20 hours for which prospective candidates had to be free from 6am until 9pm, five days a week, plus the occasional weekend. I met a woman in the Newcastle train station Starbucks kiosk who told me she had come into work for a one-hour shift.

If I even begin to describe the behaviour of employers in the care industry, we will be here all day. We're looking at a situation far worse than the simple avoidance of basic rights such as pensions and paid holiday; it's a system in which poverty is actively enforced by overweening employers whose convenience comes at the price of their employees' dignity. Marxists talk about systemic unemployment – the joblessness built into the system so that people with a job are easier to control – but systemic underemployment is fractionally worse. Poverty is still shot out indiscriminately but deliberately, like thunderbolts from the palm of Thor. In the service of profit margins, there still have to be people who can't pay their rent or feed their children. But as well as being used as industrial fodder, you also have to turn up to work.

You often hear this described as just the modern way. When we talk of things such as job security, paid time off, pensions, some human bond between the employer and the employee, some sense of symmetry, some acknowledgement of the fact that the employer creates the job but the employee creates the value, these are all now written off as belonging in a bygone era, along with coalmining and docking.

But there is nothing modern about this situation: employers have been trying to screw their staff since industrialisation began. The only difference now is that, through the erosion of collective bargaining and the amnesia of the political class, employers face very little meaningful resistance (except for unions, of course: where any opposition exists, it is from a union, and they should be applauded. But they can't do everything. They also need cultural and political support).

Here the Labour party is being culpably supine. Sheila Gilmore, the MP who put the question that elicited this response from McVey, said: "While I don't object to the principle of either universal credit or zero-hours contracts, I am concerned about this policy change." Apart from being limp to the point of irrelevance, this is immoral. The party is called Labour because it was established to represent the interests of people who work, against predators who would have them work for poverty pay. It was established so people couldn't be treated like indistinguishable pieces of meat by employers who sincerely didn't care about how they lived.

The irony of the zero-hours contract life is that, like so many mean ideas, it costs more than it saves. Security, a sense of agency, a sense of personal pride and value at work, a belief that you are doing something that is valuable to your employer – all of this is dismissed at a price. The resulting poverty is bad enough, but something important is going on that you can't count, some steady undermining of the purpose and stability and self-worth of 1.4 million people. This is the confidence of the nation's workforce we are sacrificing, so that Costa Coffee doesn't have to plan its shifts, or pay for anyone's mini-break.

But more than that, nothing distils so well the crisis in politics: that such a clear fissure between one person's rights to turn profit, against another's right to a fair day's pay, would go uncontested in Westminster. And politicians wonder why people question their relevance.

Twitter: @zoesqwilliams