The unfolding Windrush immigration scandal has reached a height few political events do. Glance at even the Daily Mail seemingly defending immigrants and it’s clear the story has evoked something deeper than any pro-migrant discussion: a sense of betrayal of that so-called British value of fairness. After all, these are long-term UK residents who arrived as children here in the 1960s, being treated as near criminals because of an immigration policy dreamed up decades later. It’s as if the rules were changed midway through the game. Except this is neither a mistake nor an anomaly, as even the former cabinet minister Sayeeda Warsi has suggested.

While Theresa May’s government may be positioning Windrush victims as having fallen foul of a terrible administrative error, the fact is that the British state actually treats immigrants generally with disdain, rather than giving them a fair hearing – and this is what enabled the Windrush scandal to happen.

Amber Rudd has now offered British citizenship to those affected, as if the government is generously giving them “greater rights” in a move of fair compensation, rather than delivering something the Windrush generation had a right to all along. But this phantom of fairness goes beyond the Home Office to other government departments. In fact, it is rooted in multiple policies affecting hundreds of thousands of people across the country as we speak.

Take the social security system, itself defined by an increasingly “hostile environment”. That May is said to have encouraged Britain to adopt a “deport first, appeal later” ethos for immigrants will sound terrifyingly familiar to anyone going through the benefits assessment system – a system marked by “remove people’s income first, appeal later”. (To date, two-thirds of appeals are won by claimants.)

In recent years, politicians have proudly promoted the reformed benefit system as fairly reaching the “really disabled”, all the while overseeing assessments that are so faulty people with Down’s syndrome are asked when they “caught it”.

Even the appeal system is rigged against the person applying for help. Official figures this month showed that legal aid cuts mean disabled people appealing their benefit rejections are denied legal support in a staggering 99% of cases.

That’s someone with severe depression, or battling multiple sclerosis exhaustion, left to take on a long, complex legal case against the government alone. It results in a disability benefit system tilted in one side’s favour: create an assessment that’s proved to wrongly deny disabled people benefits, and then deprive them of the legal aid they need to have a chance to win them back.

Or look at the benefit sanction system. This month MPs launched another inquiry into the policy of removing unemployed people’s benefits for supposed infractions – a policy that has been proved to cause destitution, and to be issued trivially for no real benefit. Meanwhile, the pot of money that jobcentre staff are meant to use to help jobseekers into work – say, bus fare to a training course or a suit for a job interview – has been cut by tens of millions of pounds since 2010.

With no sense of irony, the Department for Work and Pensions (DWP) says the changes are part of wider welfare reform “which is restoring fairness to the system”. Whether it’s towards disabled people, jobseekers, or immigrants, the default position of those with power is vilification and suspicion under the guise of “doing the right thing”.

I call it rigged Britain: where the very systems said to give a fair ride are in fact set against disadvantaged groups from the start.

The Home Office depriving Windrush citizens of their jobs, healthcare, benefits and freedom, if they could not provide multiple evidence for every year they’ve been here over 50 years, has an eerie similarity to the DWP’s sanction system depriving benefit claimants of food, housing, electricity, heat, and health because, for example, they had a heart attack when they should have been at a jobcentre appointment. Or removing their disability benefits entirely because the pile of medical notes provided by their lifelong consultants was not deemed as credible as half an hour with an Atos assessor.

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The message from ministers is that certain people shouldn’t be believed. The same government which has overseen an immigration system in which all migrants are considered illegal unless they can prove different has created a disability benefit system that works from the belief all claimants are faking and it’s their responsibility to convince the authorities otherwise. Sometimes this link is actually literal; the Guardian reported last week that a Windrush pensioner who has lived in Britain for 62 years was landed with a bill of more than £33,000 from the government for past disability benefits. She was subsequently threatened with deportation.

It’s noticeable that, while every part of the media is now covering Windrush, stories about disabled people dying after losing their benefits are continually ignored. This is not to say that Windrush is not an injustice that needs to be highlighted – it is – but to point to the fact injustice is not immune from needing to be the fashion of the day. The same politicians and newspaper editors rushing to show solidarity for Windrush citizens being treated appallingly by the Home Office are strangely silent when the benefit system is doing the same to disabled people.

Similarly, non-Windrush immigrants enduring their own problems with the Home Office should hardly hold their breath on gaining the support of the Daily Mail or the Tory frontbench. There are already reports of Home Office mistreatment spreading to Commonwealth-born citizens in countries including Kenya, Cyprus and Canada.

But then, the consequences of these attitudes are becoming harder to ignore. Just as it’s now indisputable that cries to get control of immigration have led to Windrush citizens becoming homeless or sick, rhetoric over bloated welfare bills inevitably sees disabled people going hungry and cold. If as a country we never again want to see the barbarity currently being endured by the Windrush generation, it’s surely time to consider how the state can inflict such treatment on anyone. As it stands, fairness is a British value only for the chosen few.

• Frances Ryan is a Guardian columnist